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.
Printing the Barcodes
Postnet barcodes are the small vertical lines in the lower right on your mail piece. The lines represent the Zip+4 codes. Barcodes enable automated processing of mail, which lowers mail-processing costs. Savings in processing costs at the Post Office are passed on to you through lower postage rates. The area in which the barcode is placed must be blank, as it will affect the rate of postage.
