When can an applicant voluntarily submit a substitute specification?

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.

An applicant can voluntarily submit a substitute specification at any point up to the payment of the issue fee, subject to certain conditions. 37 CFR 1.125(b) states:

Subject to § 1.312, a substitute specification, excluding the claims, may be filed at any point up to payment of the issue fee if it is accompanied by a statement that the substitute specification includes no new matter.

It’s important to note that the substitute specification must not introduce new matter and must be accompanied by a statement confirming this fact. Additionally, the claims are excluded from this voluntary submission process.