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 deadline for submitting a certified copy of a foreign priority application depends on the filing date of the U.S. application. According to MPEP 213.02:
In the case of a U.S. application filed on or after March 16, 2013, the certified copy must be filed within the later of four months from the actual filing date of the application or sixteen months from the filing date of the prior foreign application.
If the certified copy is not filed within this timeframe, the applicant must file a petition to accept a delayed submission and pay the associated fee.