14 CFR §187.15

1. (a)The fees of this part are payable to the Federal Aviation Administration by check, money order, wire transfers, draft, payable in U.S. currency and drawn on a U.S. bank, or by credit card payable in U.S. currency, prior to the provision of any service under this part.
2. (b)Applicants for the FAA services provided under this part shall pay any bank processing charges on fees collected under this part, when such charges are assessed on U.S. Government.
3. (c)Applicants for the FAA services described in Appendix A of this part shall pay bank processing charges, when such charges are assessed by banks on U.S. Government deposits.
4. (d)The fees described in appendix B of this part are payable to the Federal Aviation Administration in U.S. currency. Remittance of fees of $1,000 or more are to be paid by electronic funds transfer. Remittance of amounts less than $1,000 may be paid by electronic funds transfer, check, money order, credit card, or draft.