The DPV™ database is a U.S. Postal Service® file that includes every known address in the country. It is the most complete address database available, and can serve to validate the accuracy and completeness of known addresses. Records that cannot be matched with the DPV™ file are potentially undeliverable.

The DPV™ Product identifies whether a ZIP + 4® coded address is currently represented in the USPS® delivery file as a known address record. The DPV™ Product allows users to confirm known USPS® addresses as well as identify potential addressing issues that may hinder delivery. Correcting potential addressing issues can reduce the amount of undeliverable-as-addressed (UAA) pieces, which in turn will result in more efficient mail processing and delivery.

The DPV™ Product confirms that:

1. The known address has verifiable primary and secondary data.
2. The known address has the verifiable primary but not secondary data.
3. The address cannot be verified as a known address.

The DPV™ Product does not append any missing data or correct any address elements.

Since August 1, 2007, CASS Certified™ software has been required to use both the DPV™ and LACSLink™ products when processing address lists. This requirement ensures ZIP + 4® codes will be assigned only when the primary number of the address can be validated using the DPV™ Product, and whether the input address reflects any municipality conversions.