How can I file a request for a refund if I made a payment by mistake or paid too much?
You may file a request for a refund of any fee paid by mistake or in excess of that required. Please note that a change of purpose after the payment of a fee (e.g., when you wish to withdraw a filing for which the fee was paid) will not entitle you to a refund of such fee. The USPTO will not refund amounts of twenty-five dollars or less unless a refund is specifically requested. (See 37 CFR 1.26(a).)
All requests for refunds should be sent to:
Mail Stop 16
Director of the USPTO
P.O. Box 1450
Alexandria , VA 22313-1450