What are the requirements for filing a divisional application?

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.

The key requirements for filing a divisional application include:

• The divisional application must be filed before the patenting or abandonment of the parent application.
• It must claim only subject matter disclosed in the parent application.
• It must be filed under 37 CFR 1.53(b) (or 37 CFR 1.53(d) if it is a design application).
• The inventorship must include at least one inventor named in the parent application.
• It must claim the benefit of the parent application under 35 U.S.C. 120, 121, 365(c), or 386(c).

As stated in the MPEP:

The divisional application may be filed under 37 CFR 1.53(b) (or 37 CFR 1.53(d) if the application is a design application, but not an international design application). The inventorship in the divisional application must include at least one inventor named in the prior-filed application, and the divisional application must claim the benefit of the prior-filed application under 35 U.S.C. 120, 121, 365(c), or 386(c).