What are the requirements for filing a divisional application?

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).

To learn more:

• divisional application requirements
• patent application filing
• continuation applications