CASS Certification
Coding Accuracy Support System (CASS) improves delivery of your mail piece and maximizes postage savings by adding Zip+4 codes to your mailing list where possible. The CASS Certification process also helps determine some address problems and standardizes addresses to Postal Service formatting. The correct Zip+4 allows us to apply postal barcodes to your mail pieces, thereby qualifying your mail for Presort discounts. |
Zip+4
This system enables the Post Office to sort and dispatch mail quickly and accurately. The first 5 numbers of the zip code identify an area of the country along with the Post Office where the mail will be delivered. The additional 4 digits identify a specific range of delivery addresses. |