What information is needed to access assignment records for unpublished patent applications?

Accessing assignment records for unpublished patent applications requires specific authorization or a showing of legitimate interest. According to MPEP 301.01, for applications that are not open to the public:

Information related thereto is only obtainable upon a proper showing of written authority. For applications filed on or after September 16, 2012, the written authority must be from (A) an inventor, (B) an applicant, (C) the assignee or an assignee of an undivided part interest, (D) a patent practitioner of record, or (E) a person with written authority from (A), (B), or (C) or (D).

For applications filed before September 16, 2012, the requirements are slightly different:

For applications filed prior to September 16, 2012, the written authority must be from the applicant or applicant’s assignee or from the attorney or agent of either, or upon a showing that the person seeking such information is a bona fide prospective or actual purchaser, mortgagee, or licensee of such application.

If you’re not one of these authorized parties, you may still be able to access the records if you can demonstrate that you are a bona fide prospective or actual purchaser, mortgagee, or licensee of the application. This typically requires submitting a petition with the appropriate fee and evidence of your status.

For more information on unpublished applications, visit: unpublished applications.