Direct from the USPS: http://www.usps.com/communications/newsroom/localnews/ca/ca_2007_1203a.htm After writing Santa's response letter, place it in a stamped envelope addressed to the intended recipient. “Santa, North Pole, Alaska,” should be included as the return address in the upper left corner of the envelope. This envelope should then be placed into a larger, properly stamped First-Class Mail or Priority Mail envelope with your correct return address and mailed to: North Pole Christmas Cancellation Postmaster 5400 Mail Trail Fairbanks AK 99709-9998 North Pole postmark requests must arrive in Fairbanks, AK, before Dec. 15, 2007. Please mail your request by Dec. 10. Customers interested in obtaining the North Pole Postmark on greeting cards should mail them to the address above, following the same directions. Please make sure that the stamped envelopes are sealed and contain cards or other inserts (empty envelopes can be damaged by high-speed sorting equipment).