14 CFR § 145.55

A certificate or rating issued to a repair station located in the United States is effective from the date of issue until the repair station surrenders the certificate and the FAA accepts it for cancellation, or the FAA suspends or revokes it.

A certificate or rating issued to a repair station located outside the United States is effective from the date of issue until the last day of the 12th month after the date of issue unless the repair station surrenders the certificate and the FAA accepts it for cancellation, or the FAA suspends or revokes it. The FAA may renew the certificate or rating for 24 months if the repair station has operated in compliance with the applicable requirements of part 145 within the preceding certificate duration period.

A certificated repair station located outside the United States that applies for a renewal of its repair station certificate must—

Submit its request for renewal no later than 30 days before the repair station's current certificate expires. If a request for renewal is not made within this period, the repair station must follow the application procedures in § 145.51.

Send its request for renewal to the FAA office that has jurisdiction over the certificated repair station.

Show that the fee prescribed by the FAA has been paid.

The holder of an expired, surrendered, suspended, or revoked certificate must return it to the FAA.