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.
If you file a U.S. patent application more than 12 months after your foreign filing, your claim for priority based on that foreign application may be denied. The MPEP states:
The claim for priority cannot be based on said application, because the subsequent nonprovisional or international application designating the United States was filed more than twelve months thereafter and no petition under 37 CFR 1.55 or request under PCT Rule 26bis.3 to restore the right of priority has been granted.
However, you may still have options to restore your priority claim under certain circumstances.
For more information on 12-month rule, visit: 12-month rule.
For more information on foreign priority, visit: foreign priority.