What are the requirements for claiming foreign priority in a U.S. patent application?

To claim foreign priority in a U.S. patent application, several requirements must be met as outlined in MPEP 213. These include:

• Timely filing: The U.S. application must be filed within 12 months of the foreign application’s filing date (6 months for design patents)
• Proper claim: The priority claim must be made in an application data sheet (ADS) or in the first sentence of the specification
• Certified copy: A certified copy of the foreign application must be filed within the later of 4 months from the U.S. filing date or 16 months from the foreign filing date
• English translation: If the foreign application is not in English, a translation may be required

As stated in MPEP 213, “The claim for priority must be presented in an application data sheet (37 CFR 1.76(b)(6)) or the specification must contain or be amended to contain a specific reference to the prior foreign application.” Failure to meet these requirements may result in the loss of the priority claim.