Postal Explorer >
International Mail Manual >
4 Treatment of Outbound Mail > 420 Shortpaid and Unpaid Mail > 422 Unpaid Mail
Return all unpaid mail with return address to the sender. Imprint with stock rubber stamp R–1300–230, Returned For…Additional Postage. Enter the amount of the deficiency.
Unpaid First-Class Mail International and postcards with no return address must be forwarded to the appropriate exchange office. Endorse item with stock rubber stamp R–1300–4, Postage Due…Cents. Do not enter the amount of the deficiency.
All other unpaid mail with no return address must be sent to the appropriate mail recovery center.