USPS Address Verification

What this tool checks

This tool validates US mailing addresses against the USPS address database using CASS-certified (Coding Accuracy Support System) validation — the same standard used by commercial mail software and required for postal discounts.

For each address you enter, it returns:

• Corrected address — the standardized USPS format, including any corrections to street name spelling, abbreviations, or directionals
• ZIP+4 code — the full 9-digit ZIP code that narrows delivery to a specific side of a block or building
• DPV confirmation code — whether USPS can confirm physical delivery to this address
• Vacancy indicator — whether the address appears to be vacant

DPV confirmation codes explained

• Y — Full match. The entire address including any secondary (apt/suite) is confirmed deliverable.
• S — Primary match only. The street address is valid but the secondary (apt/suite) provided was not confirmed. Contact the recipient for the correct unit.
• D — Primary match, secondary missing. The street address is valid and USPS expects a secondary designator but none was provided.
• N — No match. USPS could not confirm delivery to this address. Double-check the street number, spelling, and ZIP code.

Note: address data is validated in real time but not stored. This tool is for verification purposes only.