People change addresses from time to time, and finding a person by using the United States Postal Service is possible if you know the last known address of the individual you are looking for. The USPS maintains a database of people who have recently moved to be able to forward mail to the new address. You can request the USPS to inform you of the new address of a person by using USPS ancillary service endorsements.

Write a short note to the person you are looking for, and place it inside an envelope. Seal the envelope, and write the last known address of the person you are looking for in the center of the envelope.

Properly label the envelope by placing your name and return address in the upper left corner on the front of the envelope. Print the word "Address Service Requested" in any of the following spots on the front of the envelope: above the delivery address block, to the left of the postage area, or below the postage area for postage stamps, meter stamps or permit imprints. By placing the words "Address Service Requested," you are instructing the USPS to advise you of the new address of the person you are looking for.

Attach the proper postage and mail the envelope via first-class mail. Wait for the mail to be returned to you with the new address of the person you are looking for. The USPS treats undeliverable-as-addressed mail labeled "Address Service Requested" in varying manners depending on the length of time since the recipient moved.

When the addressee moved within the last 12 months, the mail piece is forwarded at no charge, a separate notice of the new address is provided and an address correction fee is charged. When the addressee moved 13 to 18 months before the attempted delivery, the mail piece is returned to the sender with the new address attached; there is no charge. After 18 months or when undeliverable, the mail piece is returned with the reason for nondelivery attached; there is no charge.