What are the permissible combinations of invention categories under unity of invention?

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 unity of invention requirement allows certain combinations of invention categories in a single national stage application. According to MPEP 1893.03(d) and 37 CFR 1.475(b), the following combinations are considered to have unity of invention:

1. A product and a process specially adapted for the manufacture of said product
2. A product and a process of use of said product
3. A product, a process specially adapted for the manufacture of the said product, and a use of the said product
4. A process and an apparatus or means specifically designed for carrying out the said process
5. A product, a process specially adapted for the manufacture of the said product, and an apparatus or means specifically designed for carrying out the said process

The MPEP notes: “Otherwise, unity of invention might not be present.” This means that combinations outside these categories may be subject to a lack of unity determination.