The USPS National Customer Support Center maintains a national database of valid addresses that is used to CASS™ certify addresses. This database contains a list of all known valid addresses in the United States; however, there may be discrepancies with new or remote addresses.

If you have a valid address in your database that is changed to an incorrect address each time you run CASS It!™, the address may not be listed in the national database as a valid address. You can visit the USPS website at www.usps.gov to confirm that the address is not in the national database. When you encounter this problem, report the discrepancy to the USPS National Customer Support Center at 1-800-238-3150. Once the entry is corrected in the national database, we can correct it in our program.

Visit the USPS website at www.usps.gov to confirm that the address is not in the national database.