What happens if the fee paid to the USPTO is insufficient?

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 an applicant pays an insufficient fee to the USPTO, the Office will notify the applicant and provide an opportunity to submit the remaining balance. According to MPEP 509:

If the fee paid by the applicant is insufficient, either because the notice specified an incorrect dollar amount for the fee or because of a fee increase effective after the mailing of the notice and before payment of the fee by the applicant, the applicant should be notified in writing by the Office of the fee insufficiency and given a new time period in which to submit the remaining balance.

The notification will include:

• The reason for the additional fee requirement
• An explanation of why the original fee was incorrect or insufficient
• A new time period for submitting the remaining balance

This process helps ensure that applicants have a fair opportunity to complete their fee payments and avoid abandonment of their applications due to fee issues.