Federal Communications Commission POB 358994 Pittsburgh, PA 15251-5994 . Do not send cash. Seal your application package envelope.
Legibility is critical.
If the information on your application is not legible, you could experience a delay in processing, lose the opportunity to obtain a requested call sign or even obtain a call sign different from what you want. Prepare and address your application package exactly as directed in the previous answer. Place your application package into a second, outer envelope and seal it. The receipt date is the day the FCC receives your electronically-filed application. If the fee is not received within 10 days the application will be dismissed.