MPEP § 403 — Correspondence — With Whom Held; Customer Number Practice (Annotated Rules)

§403 Correspondence — With Whom Held; Customer Number Practice

USPTO MPEP version: BlueIron's Update: 2025-12-31

This page consolidates and annotates all enforceable requirements under MPEP § 403, including statutory authority, regulatory rules, examiner guidance, and practice notes. It is provided as guidance, with links to the ground truth sources. This is information only, it is not legal advice.

Correspondence — With Whom Held; Customer Number Practice

This section addresses Correspondence — With Whom Held; Customer Number Practice. Primary authority: 37 CFR 1.32(c)(3), 37 CFR 11.6(d), and 37 CFR 1.32(a)(1). Contains: 3 requirements, 1 prohibition, 3 guidance statements, 10 permissions, and 5 other statements.

Key Rules

Topic

POA via Customer Number

13 rules
StatutoryPermittedAlways
[mpep-403-14273beaf8e39f5b2d1aa48a]
Customer Number for POA and Address Designation
Note:
Allows using a Customer Number to designate correspondence and fee addresses, and submit practitioners with power of attorney.
A Customer Number (previously a “Payor Number”) may be used to:
  • (A) designate the correspondence address of a patent application or patent such that the correspondence address for the patent application or patent would be the address associated with the Customer Number (37 CFR 1.32(a)(5)(i));
  • (B) designate the fee address (37 CFR 1.363) of a patent such that the fee address for the patent would be the address associated with the Customer Number (37 CFR 1.32(a)(5)(ii)); and
  • (C) submit a list of practitioners such that those practitioners associated with the Customer Number would have power of attorney (37 CFR 1.32(a)(5)(iii)).
Jump to MPEP SourcePOA via Customer NumberCustomer Number PracticeCorrespondence Address
StatutoryInformativeAlways
[mpep-403-d7d04077fa523d2f1671d6f4]
Customer Number POA Requirement
Note:
Submit a list of practitioners with power of attorney for the Customer Number.

A Customer Number (previously a “Payor Number”) may be used to:

(C) submit a list of practitioners such that those practitioners associated with the Customer Number would have power of attorney (37 CFR 1.32(a)(5)(iii)).

Jump to MPEP SourcePOA via Customer NumberCustomer Number PracticePower of Attorney Requirements
StatutoryPermittedAlways
[mpep-403-a79a4d93f1b81978f0571694]
Customer Number for POA and Address Designation
Note:
Allows using a Customer Number to designate the address associated with it as an application’s correspondence or fee address, and to submit a power of attorney to registered practitioners.

Thus, a Customer Number may be used to designate the address associated with the Customer Number as the correspondence address of an application (or patent) or the fee address of a patent, and may also be used to submit a power of attorney in the application (or patent) to the registered practitioners associated with the Customer Number.

Jump to MPEP SourcePOA via Customer NumberCorrespondence Address RequirementsCustomer Number Practice
StatutoryInformativeAlways
[mpep-403-7fba80c393d9776eee65af4e]
Power of Attorney via Customer Number
Note:
An applicant can appoint all practitioners associated with a customer number by referencing the customer number in the power of attorney, without listing each practitioner individually.

The association of a list of practitioners with a Customer Number will permit an applicant to appoint all of the practitioners associated with the Customer Number merely by reference to the Customer Number in the Power of Attorney (i.e., without individually listing the practitioners in the Power of Attorney). The addition and/or deletion of a practitioner from the list of practitioners associated with a Customer Number by submitting a corresponding “Request for Customer Number Data Change” (PTO/SB/124) will result in the addition or deletion of such practitioner from the list of persons authorized to represent any applicant or assignee of the entire interest of the applicant who appointed all of the practitioners associated with such Customer Number. This will avoid the necessity for the filing of additional papers in each patent application affected by a change in the practitioners of the law firm prosecuting the application. The appointment of practitioners associated with a Customer Number is optional, in that any applicant may continue to individually name those practitioners to represent the applicant in a patent application, so long as fewer than ten patent practitioners are named. See 37 CFR 1.32(c)(3).

Jump to MPEP Source · 37 CFR 1.32(c)(3)POA via Customer NumberCustomer Number PracticePower of Attorney by Assignee
StatutoryInformativeAlways
[mpep-403-360d6c7294464ebbc16f03dc]
Change of Practitioners via Customer Number
Note:
This rule allows for the addition or removal of a practitioner from a customer number list, automatically updating their authorization in all affected patent applications without needing additional filings.

The association of a list of practitioners with a Customer Number will permit an applicant to appoint all of the practitioners associated with the Customer Number merely by reference to the Customer Number in the Power of Attorney (i.e., without individually listing the practitioners in the Power of Attorney). The addition and/or deletion of a practitioner from the list of practitioners associated with a Customer Number by submitting a corresponding “Request for Customer Number Data Change” (PTO/SB/124) will result in the addition or deletion of such practitioner from the list of persons authorized to represent any applicant or assignee of the entire interest of the applicant who appointed all of the practitioners associated with such Customer Number. This will avoid the necessity for the filing of additional papers in each patent application affected by a change in the practitioners of the law firm prosecuting the application. The appointment of practitioners associated with a Customer Number is optional, in that any applicant may continue to individually name those practitioners to represent the applicant in a patent application, so long as fewer than ten patent practitioners are named. See 37 CFR 1.32(c)(3).

Jump to MPEP Source · 37 CFR 1.32(c)(3)POA via Customer NumberCustomer Number PracticePower of Attorney by Assignee
StatutoryPermittedAlways
[mpep-403-b69d05b8f26de2c7aac72bc5]
Option to Name Practitioners via Customer Number
Note:
Applicants can appoint all practitioners associated with a Customer Number by referencing the number in the Power of Attorney, provided fewer than ten practitioners are named.

The association of a list of practitioners with a Customer Number will permit an applicant to appoint all of the practitioners associated with the Customer Number merely by reference to the Customer Number in the Power of Attorney (i.e., without individually listing the practitioners in the Power of Attorney). The addition and/or deletion of a practitioner from the list of practitioners associated with a Customer Number by submitting a corresponding “Request for Customer Number Data Change” (PTO/SB/124) will result in the addition or deletion of such practitioner from the list of persons authorized to represent any applicant or assignee of the entire interest of the applicant who appointed all of the practitioners associated with such Customer Number. This will avoid the necessity for the filing of additional papers in each patent application affected by a change in the practitioners of the law firm prosecuting the application. The appointment of practitioners associated with a Customer Number is optional, in that any applicant may continue to individually name those practitioners to represent the applicant in a patent application, so long as fewer than ten patent practitioners are named. See 37 CFR 1.32(c)(3).

Jump to MPEP Source · 37 CFR 1.32(c)(3)POA via Customer NumberCustomer Number PracticePower of Attorney by Assignee
StatutoryPermittedAlways
[mpep-403-fb198381ff8478266b5cb78b]
Design Patent Practitioners Can Only Establish POA for Design Patents
Note:
If a design patent practitioner is associated with a Customer Number, that number can only be used to establish power of attorney in design patent matters, even if other practitioners are authorized for all patent matters.

Effective January 2, 2024, the USPTO created the design patent practitioner bar for practicing before the Office in design patent matters. Design patent practitioners are registered under 37 CFR 11.6(d) and can only practice in design patent matters. 37 CFR 1.32(a)(1). In contrast, patent practitioners registered under 37 CFR 11.6(a) – (c) can practice in all patent matters, which includes design patent matters. See MPEP § 1502.02. A power of attorney naming the practitioners associated with a Customer Number may only include practitioners who are authorized to practice in the applicable patent matter. Therefore, if a design patent practitioner is associated with a Customer Number, that Customer Number can only be used to establish power of attorney in design patent matters. This applies even if a practitioner that is authorized to practice in all patent matters is also associated with the same Customer Number.

Jump to MPEP Source · 37 CFR 11.6(d)POA via Customer NumberCustomer Number PracticePower of Attorney Requirements
StatutoryRecommendedAlways
[mpep-403-c6f258f870b63f327b071476]
Practitioner Must Be Removed From Customer Number On Departure
Note:
A practitioner leaving a law firm must be promptly removed from any Customer Number they were associated with, ensuring they no longer have access to the applications linked to that number.

A law firm should promptly remove any practitioner who leaves the firm from the list of practitioners associated with any Customer Number used by the law firm, so that the practitioner will not have access to the applications associated with the Customer Number. A practitioner leaving a law firm can also remove themselves from any Customer Number used by the law firm. In order to continue representing an applicant who had appointed the practitioners associated with the Customer Number of a law firm, a practitioner leaving the law firm must obtain a new power of attorney.

Jump to MPEP SourcePOA via Customer NumberCustomer Number PracticeCorrespondence Address
StatutoryPermittedAlways
[mpep-403-e69fc6ecd43cd350383df6fc]
Practitioner Can Remove Self From Customer Number
Note:
A practitioner leaving a law firm can remove themselves from any Customer Number used by the firm, ensuring they no longer have access to related applications.

A law firm should promptly remove any practitioner who leaves the firm from the list of practitioners associated with any Customer Number used by the law firm, so that the practitioner will not have access to the applications associated with the Customer Number. A practitioner leaving a law firm can also remove themselves from any Customer Number used by the law firm. In order to continue representing an applicant who had appointed the practitioners associated with the Customer Number of a law firm, a practitioner leaving the law firm must obtain a new power of attorney.

Jump to MPEP SourcePOA via Customer NumberCustomer Number PracticeCorrespondence Address
StatutoryRequiredAlways
[mpep-403-ea5f89110992238ba0370e82]
Practitioner Must Obtain New POA to Continue Representation
Note:
A practitioner leaving a law firm must obtain a new power of attorney to continue representing an applicant associated with the firm's Customer Number.

A law firm should promptly remove any practitioner who leaves the firm from the list of practitioners associated with any Customer Number used by the law firm, so that the practitioner will not have access to the applications associated with the Customer Number. A practitioner leaving a law firm can also remove themselves from any Customer Number used by the law firm. In order to continue representing an applicant who had appointed the practitioners associated with the Customer Number of a law firm, a practitioner leaving the law firm must obtain a new power of attorney.

Jump to MPEP SourcePOA via Customer NumberCustomer Number PracticePower of Attorney by Assignee
StatutoryPermittedAlways
[mpep-403-848b6d728f2af9bc1523d9e7]
Correspondence vs Power of Attorney Customer Numbers
Note:
One customer number can be used for the correspondence address, while another can be used for appointing power of attorney practitioners.

Although Customer Numbers are designed to designate both a correspondence address and to associate one or more patent practitioners with an application, one Customer Number may be used for the correspondence address, and another Customer Number may be used for the power of attorney. As stated previously, the customer number associated with the correspondence address is the Customer Number that can be used to obtain full access to the USPTO patent electronic filing system. For example, where one customer number is associated with the correspondence address (e.g., a customer number that lists all of the practitioners at a particular firm) and a different customer number is used to appoint practitioners as having power of attorney (e.g., a customer number that lists a small number of practitioners from the particular firm as well as a few practitioners who are employees of the applicant), only the practitioners associated with the customer number being used for the correspondence address will be able to access the application in the USPTO patent electronic filing system.

Jump to MPEP SourcePOA via Customer NumberCorrespondence Address RequirementsCustomer Number Practice
StatutoryPermittedAlways
[mpep-403-28e4689fde8bc28dabf2bc76]
Correspondence Customer Number Required for USPTO Access
Note:
The customer number associated with the correspondence address is required to obtain full access to the USPTO patent electronic filing system.

Although Customer Numbers are designed to designate both a correspondence address and to associate one or more patent practitioners with an application, one Customer Number may be used for the correspondence address, and another Customer Number may be used for the power of attorney. As stated previously, the customer number associated with the correspondence address is the Customer Number that can be used to obtain full access to the USPTO patent electronic filing system. For example, where one customer number is associated with the correspondence address (e.g., a customer number that lists all of the practitioners at a particular firm) and a different customer number is used to appoint practitioners as having power of attorney (e.g., a customer number that lists a small number of practitioners from the particular firm as well as a few practitioners who are employees of the applicant), only the practitioners associated with the customer number being used for the correspondence address will be able to access the application in the USPTO patent electronic filing system.

Jump to MPEP SourcePOA via Customer NumberCorrespondence Address RequirementsCustomer Number Practice
StatutoryInformativeAlways
[mpep-403-bb49eadbd711524e2f5db0d5]
Correspondence Customer Number Limits Access
Note:
Only practitioners associated with the customer number for correspondence can access the application in the USPTO patent electronic filing system.

Although Customer Numbers are designed to designate both a correspondence address and to associate one or more patent practitioners with an application, one Customer Number may be used for the correspondence address, and another Customer Number may be used for the power of attorney. As stated previously, the customer number associated with the correspondence address is the Customer Number that can be used to obtain full access to the USPTO patent electronic filing system. For example, where one customer number is associated with the correspondence address (e.g., a customer number that lists all of the practitioners at a particular firm) and a different customer number is used to appoint practitioners as having power of attorney (e.g., a customer number that lists a small number of practitioners from the particular firm as well as a few practitioners who are employees of the applicant), only the practitioners associated with the customer number being used for the correspondence address will be able to access the application in the USPTO patent electronic filing system.

Jump to MPEP SourcePOA via Customer NumberCorrespondence Address RequirementsCustomer Number Practice
Topic

Correspondence Address Requirements

7 rules
StatutoryInformativeAlways
[mpep-403-a271f66fb21b6a4f4a236d50]
Attorney/Agent Correspondence Address Requirement
Note:
When an attorney or agent is appointed to prosecute an application, correspondence must be sent to them unless a different address is specified.

37 CFR 1.33 states that when an attorney or agent has been duly appointed to prosecute an application, correspondence will be held with the attorney or agent unless some other correspondence address has been given. If an attorney or agent of record assigns a correspondence address which is different than an address where the attorney or agent normally receives mail, the attorney or agent is reminded that (1) 37 CFR 11.106 requires the attorney or agent to keep information obtained by attorney/agent – client relationship in confidence; and (2) the attorney or agent is still responsible for responding to any notice or action from the Office. See 37 CFR 11.101, 11.103 and 11.804. Double correspondence with an applicant and their attorney, or with two representatives, will not be undertaken. See MPEP §§ 403.01(a), 403.01(b), 403.02, and 714.01(d).

Jump to MPEP Source · 37 CFR 1.33Correspondence Address RequirementsCorrespondence with the OfficeCorrespondence Address
StatutoryInformativeAlways
[mpep-403-03a981d093a6f6cef216b02d]
Confidentiality and Response Responsibility for Changed Address
Note:
Attorneys or agents must maintain confidentiality of client information and respond to Office communications even if they change their correspondence address.

37 CFR 1.33 states that when an attorney or agent has been duly appointed to prosecute an application, correspondence will be held with the attorney or agent unless some other correspondence address has been given. If an attorney or agent of record assigns a correspondence address which is different than an address where the attorney or agent normally receives mail, the attorney or agent is reminded that (1) 37 CFR 11.106 requires the attorney or agent to keep information obtained by attorney/agent – client relationship in confidence; and (2) the attorney or agent is still responsible for responding to any notice or action from the Office. See 37 CFR 11.101, 11.103 and 11.804. Double correspondence with an applicant and their attorney, or with two representatives, will not be undertaken. See MPEP §§ 403.01(a), 403.01(b), 403.02, and 714.01(d).

Jump to MPEP Source · 37 CFR 1.33Correspondence Address RequirementsCorrespondence with the OfficeCorrespondence Address
StatutoryInformativeAlways
[mpep-403-0b77b00d77e83e2bb544a677]
Customer Number Preempts Other Addresses
Note:
The correspondence address will be determined by the Customer Number provided, overriding any other addresses in the application.

As the Office will not recognize more than one correspondence address (37 CFR 1.33(a)), any inconsistencies between the correspondence address resulting from a Customer Number being provided in an application for the correspondence address and any other correspondence address provided in that application will generally be resolved in favor of the address of the Customer Number or the application data sheet (37 CFR 1.76(d)). Due to the prohibition against double correspondence in an application (37 CFR 1.33(a)), an applicant will be permitted to provide only a single number at a time as the Customer Number for the correspondence address. Applicants are strongly cautioned not to attempt to appoint more than one Customer Number for a particular purpose (e.g., correspondence address) in a single communication, as such action will not have a cumulative effect.

Jump to MPEP Source · 37 CFR 1.33(a))Correspondence Address RequirementsCustomer Number PracticeCorrespondence with the Office
StatutoryPermittedAlways
[mpep-403-15cf608921dc9bf19708a9b4]
Single Customer Number for Correspondence Address
Note:
Applicants must provide only one Customer Number at a time for the correspondence address to avoid double correspondence and ensure clarity.

As the Office will not recognize more than one correspondence address (37 CFR 1.33(a)), any inconsistencies between the correspondence address resulting from a Customer Number being provided in an application for the correspondence address and any other correspondence address provided in that application will generally be resolved in favor of the address of the Customer Number or the application data sheet (37 CFR 1.76(d)). Due to the prohibition against double correspondence in an application (37 CFR 1.33(a)), an applicant will be permitted to provide only a single number at a time as the Customer Number for the correspondence address. Applicants are strongly cautioned not to attempt to appoint more than one Customer Number for a particular purpose (e.g., correspondence address) in a single communication, as such action will not have a cumulative effect.

Jump to MPEP Source · 37 CFR 1.33(a))Correspondence Address RequirementsCustomer Number PracticeCorrespondence with the Office
StatutoryRequiredAlways
[mpep-403-3a7a501ef63d86f5eda9fe0a]
Correspondence Address Required for Notification
Note:
An applicant must provide a correspondence address for the Office to notify them about missing parts in their patent application.

If a patent application as filed has been accorded a filing date but is not complete, the applicant is notified and given a period of time within which to file the missing parts to complete the application and pay the applicable surcharge. See MPEP § 601.01et seq. for a discussion of the requirements for a complete application. In order for the Office to so notify the applicant, a correspondence address must also be provided by the applicant. The address may be different from the post office address of the applicant. For example, the address of the applicant’s registered attorney or agent may be used as the correspondence address. If the applicant fails to provide the Office with a correspondence address, the Office will be unable to provide the applicant with notification to complete the application and to pay the surcharge as set forth in 37 CFR 1.16(f) for nonprovisional applications and 37 CFR 1.16(g) for provisional applications. In such a case, the applicant will be considered to have constructive notice as of the filing date that the application must be completed and the applicant will have 2 months from the filing date in which to do so before abandonment occurs.

Jump to MPEP Source · 37 CFR 1.16(f)Correspondence Address RequirementsCorrespondence with the OfficeCorrespondence Address
StatutoryPermittedAlways
[mpep-403-b2d1b3cc476f140dd852d839]
Correspondence Address Required for Notification
Note:
The applicant must provide a correspondence address to receive notifications about missing application parts and required actions.

If a patent application as filed has been accorded a filing date but is not complete, the applicant is notified and given a period of time within which to file the missing parts to complete the application and pay the applicable surcharge. See MPEP § 601.01et seq. for a discussion of the requirements for a complete application. In order for the Office to so notify the applicant, a correspondence address must also be provided by the applicant. The address may be different from the post office address of the applicant. For example, the address of the applicant’s registered attorney or agent may be used as the correspondence address. If the applicant fails to provide the Office with a correspondence address, the Office will be unable to provide the applicant with notification to complete the application and to pay the surcharge as set forth in 37 CFR 1.16(f) for nonprovisional applications and 37 CFR 1.16(g) for provisional applications. In such a case, the applicant will be considered to have constructive notice as of the filing date that the application must be completed and the applicant will have 2 months from the filing date in which to do so before abandonment occurs.

Jump to MPEP Source · 37 CFR 1.16(f)Correspondence Address RequirementsCorrespondence with the OfficeIntervening Rights After Reinstatement
StatutoryInformativeAlways
[mpep-403-e0e29b31be8b4fe4f4084ba8]
Correspondence Address Required for Notification
Note:
The applicant must provide a correspondence address to receive notifications and payment requirements.

If a patent application as filed has been accorded a filing date but is not complete, the applicant is notified and given a period of time within which to file the missing parts to complete the application and pay the applicable surcharge. See MPEP § 601.01et seq. for a discussion of the requirements for a complete application. In order for the Office to so notify the applicant, a correspondence address must also be provided by the applicant. The address may be different from the post office address of the applicant. For example, the address of the applicant’s registered attorney or agent may be used as the correspondence address. If the applicant fails to provide the Office with a correspondence address, the Office will be unable to provide the applicant with notification to complete the application and to pay the surcharge as set forth in 37 CFR 1.16(f) for nonprovisional applications and 37 CFR 1.16(g) for provisional applications. In such a case, the applicant will be considered to have constructive notice as of the filing date that the application must be completed and the applicant will have 2 months from the filing date in which to do so before abandonment occurs.

Jump to MPEP Source · 37 CFR 1.16(f)Correspondence Address RequirementsFiling, Search & Examination FeesCorrespondence with the Office
Topic

Customer Number Practice

7 rules
StatutoryInformativeAlways
[mpep-403-25f06cb1d05f3ce054468a65]
Change Customer Number Through USPTO System Required
Note:
Requests for changes to customer numbers must be made through the USPTO patent electronic filing system.

The Office will accept requests for changes to the Customer Number information through the USPTO patent electronic filing system. See MPEP § 502.05 for information pertaining to the USPTO patent electronic filing system.

Jump to MPEP SourceCustomer Number PracticeCorrespondence Address
StatutoryInformativeAlways
[mpep-403-5b26b4711fb97ec2d3867463]
Forms for Customer Number Practice Required
Note:
The rule requires the use of specific forms for requesting and changing customer numbers, including a request for a new number, data changes, and address modifications.
The following forms are suggested for use with the Customer Number practice:
  • (A) the “Request for Customer Number” (PTO/SB/125) to request a Customer Number;
  • (B) the “Request for Customer Number Data Change” (PTO/SB/124) to request a change in the data (address or list of practitioners) associated with an existing Customer Number;
  • (C) the “Change of Correspondence Address, Application” (PTO/AIA/122 for applications filed on or after September 16, 2012, or PTO/SB/122 for applications filed before September 16, 2012) to change the correspondence address of an individual application to the address associated with a Customer Number; and
  • (D) the “Change of Correspondence Address, Patent” (PTO/AIA/123 for applications filed on or after September 16, 2012, or PTO//SB/123 for applications filed before September 16, 2012) to change the correspondence address of an individual patent to the address associated with a Customer Number.
Jump to MPEP SourceCustomer Number PracticeCorrespondence AddressAIA Effective Dates
StatutoryInformativeAlways
[mpep-403-db976f1c7407a5db8803a1db]
Customer Number Practice Does Not Permit Law Firm Appointment
Note:
The Customer Number practice does not allow an appointment of a law firm but permits the appointment of all practitioners associated with a specified Customer Number.

The Customer Number practice does not affect the prohibition against, and does not amount to, an appointment of a law firm (rather than specified practitioners). The Office prohibits an appointment of a specified law firm because the Office cannot ascertain from its records whether a particular practitioner submitting a paper to the Office is associated with the law firm specified in an appointment. The Office will permit an appointment of all of the practitioners associated with a specified Customer Number because the Office can ascertain from its records for the specified Customer Number whether a particular practitioner is associated with that Customer Number.

Jump to MPEP SourceCustomer Number PracticeCorrespondence AddressPractitioner Recognition and Conduct
StatutoryProhibitedAlways
[mpep-403-88af4b83345dd80af022bc8d]
Requirement for Customer Number Practice
Note:
The Office requires an appointment of all practitioners associated with a specified Customer Number to be permitted, as the Office can ascertain their association from records.

The Customer Number practice does not affect the prohibition against, and does not amount to, an appointment of a law firm (rather than specified practitioners). The Office prohibits an appointment of a specified law firm because the Office cannot ascertain from its records whether a particular practitioner submitting a paper to the Office is associated with the law firm specified in an appointment. The Office will permit an appointment of all of the practitioners associated with a specified Customer Number because the Office can ascertain from its records for the specified Customer Number whether a particular practitioner is associated with that Customer Number.

Jump to MPEP SourceCustomer Number PracticeCorrespondence AddressPractitioner Recognition and Conduct
StatutoryPermittedAlways
[mpep-403-dbd6b15cb4df71d4f90dcb4f]
Customer Number Practice Permitted for Appointment of Practitioners
Note:
The Office permits an appointment of all practitioners associated with a specified Customer Number as it can verify from its records whether each practitioner is linked to that Customer Number.

The Customer Number practice does not affect the prohibition against, and does not amount to, an appointment of a law firm (rather than specified practitioners). The Office prohibits an appointment of a specified law firm because the Office cannot ascertain from its records whether a particular practitioner submitting a paper to the Office is associated with the law firm specified in an appointment. The Office will permit an appointment of all of the practitioners associated with a specified Customer Number because the Office can ascertain from its records for the specified Customer Number whether a particular practitioner is associated with that Customer Number.

Jump to MPEP SourceCustomer Number PracticeCorrespondence AddressPractitioner Recognition and Conduct
StatutoryRecommendedAlways
[mpep-403-b855a61219062c0a3bd9bf2f]
Remove Sponsorship of Departing Support Staff
Note:
A practitioner must remove sponsorship of any support staff individual who leaves the firm to prevent access to associated patent applications.

Similarly, a practitioner who has a USPTO patent electronic filing system account should remove sponsorship of any support staff individual when that individual leaves the firm so that the support staff individual will not have access to any applications associated with any Customer Number linked to the practitioner.

Jump to MPEP SourceCustomer Number PracticeCorrespondence AddressAccess to Patent Application Files (MPEP 101-106)
StatutoryRecommendedAlways
[mpep-403-b3258b9d0f2d2c28879396f6]
Customer Number Correspondence Must Use Mail Stop EBC
Note:
All correspondence related to a Customer Number, including requests for a Customer Number, must be addressed to the designated Mail Stop EBC.

The Office has created a Mail Stop designation for correspondence related to a Customer Number (“Mail Stop EBC”), and all correspondence related to a Customer Number (e.g., requests for a Customer Number) should be addressed to this mail stop designation.

Jump to MPEP SourceCustomer Number PracticeCorrespondence Address
Topic

Identifying the Application

3 rules
StatutoryInformativeAlways
[mpep-403-ba071da3e7f8f3d1ab928498]
Notification for Missing Application Components
Note:
Applicants must be notified and given time to file missing parts and pay surcharges if their application is filed but incomplete.

If a patent application as filed has been accorded a filing date but is not complete, the applicant is notified and given a period of time within which to file the missing parts to complete the application and pay the applicable surcharge. See MPEP § 601.01et seq. for a discussion of the requirements for a complete application. In order for the Office to so notify the applicant, a correspondence address must also be provided by the applicant. The address may be different from the post office address of the applicant. For example, the address of the applicant’s registered attorney or agent may be used as the correspondence address. If the applicant fails to provide the Office with a correspondence address, the Office will be unable to provide the applicant with notification to complete the application and to pay the surcharge as set forth in 37 CFR 1.16(f) for nonprovisional applications and 37 CFR 1.16(g) for provisional applications. In such a case, the applicant will be considered to have constructive notice as of the filing date that the application must be completed and the applicant will have 2 months from the filing date in which to do so before abandonment occurs.

Jump to MPEP Source · 37 CFR 1.16(f)Identifying the ApplicationFee RequirementsLate Payment and Reinstatement
StatutoryPermittedAlways
[mpep-403-d91cbf6f2714c09e1a19ee74]
Correspondence Address May Differ From Post Office Address
Note:
The address used for correspondence with the patent office may be different from the applicant's post office address.

If a patent application as filed has been accorded a filing date but is not complete, the applicant is notified and given a period of time within which to file the missing parts to complete the application and pay the applicable surcharge. See MPEP § 601.01et seq. for a discussion of the requirements for a complete application. In order for the Office to so notify the applicant, a correspondence address must also be provided by the applicant. The address may be different from the post office address of the applicant. For example, the address of the applicant’s registered attorney or agent may be used as the correspondence address. If the applicant fails to provide the Office with a correspondence address, the Office will be unable to provide the applicant with notification to complete the application and to pay the surcharge as set forth in 37 CFR 1.16(f) for nonprovisional applications and 37 CFR 1.16(g) for provisional applications. In such a case, the applicant will be considered to have constructive notice as of the filing date that the application must be completed and the applicant will have 2 months from the filing date in which to do so before abandonment occurs.

Jump to MPEP Source · 37 CFR 1.16(f)Identifying the ApplicationCorrespondence Address RequirementsFiling, Search & Examination Fees
StatutoryRequiredAlways
[mpep-403-e2d8c44c8f67bb069970db19]
Application Must Be Completed Within Two Months
Note:
The applicant must complete the patent application and pay any required surcharges within two months of filing, otherwise it will be abandoned.

If a patent application as filed has been accorded a filing date but is not complete, the applicant is notified and given a period of time within which to file the missing parts to complete the application and pay the applicable surcharge. See MPEP § 601.01et seq. for a discussion of the requirements for a complete application. In order for the Office to so notify the applicant, a correspondence address must also be provided by the applicant. The address may be different from the post office address of the applicant. For example, the address of the applicant’s registered attorney or agent may be used as the correspondence address. If the applicant fails to provide the Office with a correspondence address, the Office will be unable to provide the applicant with notification to complete the application and to pay the surcharge as set forth in 37 CFR 1.16(f) for nonprovisional applications and 37 CFR 1.16(g) for provisional applications. In such a case, the applicant will be considered to have constructive notice as of the filing date that the application must be completed and the applicant will have 2 months from the filing date in which to do so before abandonment occurs.

Jump to MPEP Source · 37 CFR 1.16(f)Identifying the ApplicationCorrespondence Address RequirementsFiling, Search & Examination Fees
Topic

AIA Effective Dates

2 rules
StatutoryInformativeAlways
[mpep-403-4095301c5b2cb42f8b860b7e]
Correspondence Requirements for Filing Dates
Note:
Describes the correspondence requirements for applications filed before and after September 16, 2012.

See MPEP § 403.01(a) for additional information pertaining to correspondence in applications filed on or after September 16, 2012. See MPEP § 403.01(b) for additional information pertaining to correspondence in applications filed before September 16, 2012.

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesAIA vs Pre-AIA Practice
StatutoryInformativeAlways
[mpep-403-1dcb61c231f4990ac24d7799]
Change Patent Correspondence to Customer Number
Note:
This rule requires changing the correspondence address for a patent application to match the address associated with a Customer Number.

The following forms are suggested for use with the Customer Number practice:

(D) the “Change of Correspondence Address, Patent” (PTO/AIA/123 for applications filed on or after September 16, 2012, or PTO//SB/123 for applications filed before September 16, 2012) to change the correspondence address of an individual patent to the address associated with a Customer Number.

Jump to MPEP SourceAIA Effective DatesAIA Overview and Effective DatesCorrespondence Address Requirements
Topic

Private PAIR Access

2 rules
StatutoryPermittedAlways
[mpep-403-6858b107e0a8746e1ce3e829]
Same or Different Customer Numbers for Addresses and Practitioners Allowed
Note:
Applicants can use the same or different customer numbers for correspondence, fee, and practitioner addresses.

Applicant may use either the same or different customer number(s) for the correspondence address, the fee address and/or a list of practitioners. The customer number associated with the correspondence address is the Customer Number that can be used to obtain full access to the USPTO patent electronic filing system at www.uspto.gov/PatentCenter. See MPEP § 1730 for additional information regarding the USPTO patent electronic filing system.

Jump to MPEP SourcePrivate PAIR AccessCorrespondence Address RequirementsCustomer Number Practice
StatutoryPermittedAlways
[mpep-403-c2ed74b3121b3ff382cb176a]
Customer Number for Correspondence Address Required
Note:
The customer number associated with the correspondence address is required to access the USPTO patent electronic filing system.

Applicant may use either the same or different customer number(s) for the correspondence address, the fee address and/or a list of practitioners. The customer number associated with the correspondence address is the Customer Number that can be used to obtain full access to the USPTO patent electronic filing system at www.uspto.gov/PatentCenter. See MPEP § 1730 for additional information regarding the USPTO patent electronic filing system.

Jump to MPEP SourcePrivate PAIR AccessElectronic Access SystemsCorrespondence Address Requirements
Topic

Practitioner Recognition and Conduct

2 rules
StatutoryPermittedAlways
[mpep-403-f9edd31f1218833f9cb04f1c]
Design Patent Practitioners Can Only Practice in Design Matters
Note:
Design patent practitioners registered under 37 CFR 11.6(d) are restricted to practicing only in design patent matters, not all patent types.

Effective January 2, 2024, the USPTO created the design patent practitioner bar for practicing before the Office in design patent matters. Design patent practitioners are registered under 37 CFR 11.6(d) and can only practice in design patent matters. 37 CFR 1.32(a)(1). In contrast, patent practitioners registered under 37 CFR 11.6(a) – (c) can practice in all patent matters, which includes design patent matters. See MPEP § 1502.02. A power of attorney naming the practitioners associated with a Customer Number may only include practitioners who are authorized to practice in the applicable patent matter. Therefore, if a design patent practitioner is associated with a Customer Number, that Customer Number can only be used to establish power of attorney in design patent matters. This applies even if a practitioner that is authorized to practice in all patent matters is also associated with the same Customer Number.

Jump to MPEP Source · 37 CFR 11.6(d)Practitioner Recognition and ConductPOA via Customer NumberCustomer Number Practice
StatutoryPermittedAlways
[mpep-403-64f0c2a78ee27616b23bda06]
All Patent Matters Including Design Patents
Note:
Patent practitioners registered under 37 CFR 11.6(a)-(c) can practice in all patent matters, including design patents.

Effective January 2, 2024, the USPTO created the design patent practitioner bar for practicing before the Office in design patent matters. Design patent practitioners are registered under 37 CFR 11.6(d) and can only practice in design patent matters. 37 CFR 1.32(a)(1). In contrast, patent practitioners registered under 37 CFR 11.6(a) – (c) can practice in all patent matters, which includes design patent matters. See MPEP § 1502.02. A power of attorney naming the practitioners associated with a Customer Number may only include practitioners who are authorized to practice in the applicable patent matter. Therefore, if a design patent practitioner is associated with a Customer Number, that Customer Number can only be used to establish power of attorney in design patent matters. This applies even if a practitioner that is authorized to practice in all patent matters is also associated with the same Customer Number.

Jump to MPEP Source · 37 CFR 11.6(d)Practitioner Recognition and ConductPOA via Customer NumberCustomer Number Practice
Topic

Correspondence with the Office

1 rules
StatutoryInformativeAlways
[mpep-403-9a93ca9866f977e3d8d0a569]
Double Correspondence Not Allowed With Applicant and Attorney
Note:
Correspondence will not be sent to both an applicant and their attorney, or to two representatives.

37 CFR 1.33 states that when an attorney or agent has been duly appointed to prosecute an application, correspondence will be held with the attorney or agent unless some other correspondence address has been given. If an attorney or agent of record assigns a correspondence address which is different than an address where the attorney or agent normally receives mail, the attorney or agent is reminded that (1) 37 CFR 11.106 requires the attorney or agent to keep information obtained by attorney/agent – client relationship in confidence; and (2) the attorney or agent is still responsible for responding to any notice or action from the Office. See 37 CFR 11.101, 11.103 and 11.804. Double correspondence with an applicant and their attorney, or with two representatives, will not be undertaken. See MPEP §§ 403.01(a), 403.01(b), 403.02, and 714.01(d).

Jump to MPEP Source · 37 CFR 1.33Correspondence with the OfficeCustomer Number PracticeCorrespondence Address
Topic

Types of Office Actions

1 rules
StatutoryInformativeAlways
[mpep-403-e416b106f16903ddec80247d]
Office Action Including Paragraph and Copy to Applicant
Note:
When the first reply is received directly from the applicant, include a specific paragraph in the Office action and send a copy of the action to the applicant. Refer to MPEP sections 403 and 714.01 for details.

1. The first time a reply is received directly from applicant, include this paragraph in the Office action and send a copy of the action to the applicant. See MPEP §§ 403 and 714.01.

37 CFR 1.77Types of Office ActionsResponse to Office Action Requirements (37 CFR 1.111)Examiner's Action (37 CFR 1.104)
Topic

Official Gazette – Patents (MPEP 1730)

1 rules
StatutoryRequiredAlways
[mpep-403-4c72fdee96b3745c7246f610]
Electronic Requests Must Comply With Payor Number Requirements
Note:
Such electronic requests must adhere to the requirements outlined in the Notice published in the Federal Register and Official Gazette regarding the extension of payor number practice for pending patent applications.

Such electronic requests must comply with the requirements set forth in the Notice entitled “Extension of the Payor Number Practice (through “Customer Numbers”) to Matters Involving Pending Patent Applications,” published in the Federal Register at 61 FR 54622, 54623-24 (October 21, 1996), and in the Official Gazette at 1191 O. G. 187, 188-89 (October 29, 1996).

Jump to MPEP SourceOfficial Gazette – Patents (MPEP 1730)
Topic

Limited Recognition Practitioners

1 rules
StatutoryInformativeAlways
[mpep-403-e3315eae27cb01c910d9e7f1]
Design Patent Practitioners Can Only Practice in Design Matters
Note:
Practitioners registered under 37 CFR 11.6(d) can only handle design patent matters, not all types of patents.

Effective January 2, 2024, the USPTO created the design patent practitioner bar for practicing before the Office in design patent matters. Design patent practitioners are registered under 37 CFR 11.6(d) and can only practice in design patent matters. 37 CFR 1.32(a)(1). In contrast, patent practitioners registered under 37 CFR 11.6(a) – (c) can practice in all patent matters, which includes design patent matters. See MPEP § 1502.02. A power of attorney naming the practitioners associated with a Customer Number may only include practitioners who are authorized to practice in the applicable patent matter. Therefore, if a design patent practitioner is associated with a Customer Number, that Customer Number can only be used to establish power of attorney in design patent matters. This applies even if a practitioner that is authorized to practice in all patent matters is also associated with the same Customer Number.

Jump to MPEP Source · 37 CFR 11.6(d)Limited Recognition PractitionersPractitioner Recognition and ConductPOA via Customer Number
Topic

Power of Attorney Requirements

1 rules
StatutoryInformativeAlways
[mpep-403-7beeddffd96fde7610d4bc1c]
Power of Attorney for Design Patents Only
Note:
A power of attorney can only be established with a design patent practitioner associated with a Customer Number for design patent matters.

Effective January 2, 2024, the USPTO created the design patent practitioner bar for practicing before the Office in design patent matters. Design patent practitioners are registered under 37 CFR 11.6(d) and can only practice in design patent matters. 37 CFR 1.32(a)(1). In contrast, patent practitioners registered under 37 CFR 11.6(a) – (c) can practice in all patent matters, which includes design patent matters. See MPEP § 1502.02. A power of attorney naming the practitioners associated with a Customer Number may only include practitioners who are authorized to practice in the applicable patent matter. Therefore, if a design patent practitioner is associated with a Customer Number, that Customer Number can only be used to establish power of attorney in design patent matters. This applies even if a practitioner that is authorized to practice in all patent matters is also associated with the same Customer Number.

Jump to MPEP Source · 37 CFR 11.6(d)Power of Attorney RequirementsPower of AttorneyPOA via Customer Number
Topic

Form Paragraph Usage

1 rules
MPEP GuidanceRecommendedAlways
[mpep-403-932ad5d1d1091506e249ff70]
Form Paragraph 4.01 Required for Double Correspondence
Note:
If double correspondence is attempted, form paragraph 4.01 must be included in the next Office action.

If double correspondence is attempted, form paragraph 4.01 should be included in the next Office action.

Jump to MPEP SourceForm Paragraph UsageForm ParagraphsExaminer's Action (37 CFR 1.104)

Examiner Form Paragraphs

Examiner form paragraphs are standard language that you might see in an Office Action or communication from the USPTO. Examiners have latitude to change the form paragraphs, but you will often see this exact language.

¶ 4.01 ¶ 4.01 Double Correspondence

Applicant has appointed an attorney or agent to conduct all business before the Patent and Trademark Office. Double correspondence with an applicant and applicant's attorney or agent will not be undertaken. Accordingly, applicant is required to conduct all future correspondence with this Office through the attorney or agent of record. See 37 CFR 1.33 .

Citations

Primary topicCitation
37 CFR § 1.136
Correspondence Address Requirements
Identifying the Application
37 CFR § 1.16(f)
Correspondence Address Requirements
Identifying the Application
37 CFR § 1.16(g)
Limited Recognition Practitioners
POA via Customer Number
Power of Attorney Requirements
Practitioner Recognition and Conduct
37 CFR § 1.32(a)(1)
POA via Customer Number37 CFR § 1.32(a)(5)(i)
POA via Customer Number37 CFR § 1.32(a)(5)(ii)
POA via Customer Number37 CFR § 1.32(a)(5)(iii)
POA via Customer Number37 CFR § 1.32(c)(3)
Correspondence Address Requirements
Correspondence with the Office
37 CFR § 1.33
Correspondence Address Requirements37 CFR § 1.33(a)
POA via Customer Number37 CFR § 1.363
Correspondence Address Requirements37 CFR § 1.76(d)
Correspondence Address Requirements
Correspondence with the Office
37 CFR § 11.101
Correspondence Address Requirements
Correspondence with the Office
37 CFR § 11.106
Limited Recognition Practitioners
POA via Customer Number
Power of Attorney Requirements
Practitioner Recognition and Conduct
37 CFR § 11.6(a)
Limited Recognition Practitioners
POA via Customer Number
Power of Attorney Requirements
Practitioner Recognition and Conduct
37 CFR § 11.6(d)
Limited Recognition Practitioners
POA via Customer Number
Power of Attorney Requirements
Practitioner Recognition and Conduct
MPEP § 1502.02
Private PAIR AccessMPEP § 1730
Types of Office ActionsMPEP § 403
AIA Effective Dates
Correspondence Address Requirements
Correspondence with the Office
MPEP § 403.01(a)
AIA Effective DatesMPEP § 403.01(b)
Customer Number PracticeMPEP § 502.05
Correspondence Address Requirements
Identifying the Application
MPEP § 601.01
Form Paragraph UsageForm Paragraph § 4.01

Source Text from USPTO’s MPEP

This is an exact copy of the MPEP from the USPTO. It is here for your reference to see the section in context.

BlueIron Last Updated: 2025-12-31