All addresses are cross-referenced against a Postmaster database for accuracy.

Approximately 98% of all addresses have nine digit zip codes (the original 5-digit zip code plus a 4-digit add-on code).

Nine digit zip codes are required for bulk mailing, pre-sorted mail, and also increase the accuracy and speed of mail delivery.
 

CALL

1 800 808 LIST or 1 800 808 5478

for more details