What is an application number and how is it assigned?
An application number consists of a series code and a serial number. It is assigned by the Office of Patent Application Processing (OPAP) immediately after mail has been opened. For applications filed using the USPTO patent electronic filing system, EFS-Web provides an Acknowledgement Receipt containing a time and date stamp, application number, and confirmation number.
The MPEP states: ‘Application numbers consisting of a series code and a serial number are assigned by the Office of Patent Application Processing (OPAP) immediately after mail has been opened.’ (MPEP 503)
Topics:
MPEP 500 - Receipt and Handling of Mail and Papers,
MPEP 503 - Application Number and Filing Receipt,
Patent Law,
Patent Procedure