What is a ‘substitute’ application in patent law?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

A ‘substitute’ application in patent law is essentially a duplicate of an earlier application that was abandoned before the filing of the later application. The MPEP provides the following definition:

A “substitute” application is in essence the duplicate of an application by the same applicant abandoned before the filing of the later application.

Key points about substitute applications:

• It does not obtain the benefit of the filing date of the prior application
• Current practice does not require applicants to insert references to the earlier application in the specification
• Applicants should call attention to the earlier application

The USPTO uses a specific form paragraph (2.07) to remind applicants of possible substitute status:

Applicant refers to this application as a “substitute” of Application No. [1], filed [2]. The term “substitute” is used to designate an application which is in essence the duplicate of an application by the same applicant abandoned before the filing of the later application. A “substitute” does not obtain the benefit of the filing date of the prior application.