How does the ‘first foreign application’ rule affect priority claims?

The ‘first foreign application’ rule states that the priority period is calculated from the earliest foreign filing, with some exceptions. This means:

• Priority can only be claimed to the first application filed for the invention.
• If multiple foreign applications were filed, only the earliest can serve as the basis for priority.
• Applications filed in non-recognized countries are disregarded for priority purposes.

The MPEP provides an example: If an inventor has filed an application in France on October 4, 1981, and an identical application in the United Kingdom on March 3, 1982, and then files in the United States on February 2, 1983, the inventor is not entitled to the right of priority at all; the inventor would not be entitled to the benefit of the date of the French application since this application was filed more than twelve months before the U.S. application, and the inventor would not be entitled to the benefit of the date of the United Kingdom application since this application is not the first one filed. (MPEP 213.03)

To learn more:

• First foreign application
• Priority claim
• Multiple foreign filings