What is Delivery Point Validation (DPV)?

Delivery Point Validation™ (DPV®) is the process of verifying that an address is actually deliverable, meaning that mail can be sent to that address. A submitted address is checked against an authoritative database, and if there's a matching entry in the database, the submitted address is declared "valid." If there's no matching address in the database, the address is "invalid," and mail cannot be shipped there.

Additionally, when you submit an address for DPV, the addresss is cleaned up and formatted according to USPS standards, complete with ZIP+4. DPV speeds the processing and delivery of mail, and can qualify mail for bulk mailing discounts.

Point of delivery

A delivery point is the final destination for a letter or package carried by the postal service. It can be a PO Box, a mailbox at the curb, or a mail slot in a front door. It's the handoff point between the mail carrier and the recipient.

Delivery points are different from street addresses. A single street address may have multiple delivery points, such as individual units in an apartment building. To identify delivery points individually, the USPS gives each one a unique 11-digit number. The number is composed of the delivery point's nine-digit ZIP+4 Code plus an extra two digits that narrow the designation to the delivery point itself. These 11 digits, plus an additional check digit, are converted into a barcode that's printed on the envelope or packaging when your mail is sorted at the post office.

A little side note here: Since ZIP+4 Codes do change occasionally, so do Delivery Point Barcodes. Instead of using a Delivery Point Barcode as an address's unique identifier in your dataset, we recommend using the standardized address, minus the ZIP Code, as a string. See this article for the full explanation.


In general terms, address validation (also called address verification) is the process of making sure an address is serviceable by a postal carrier. It's asking the question, "Can I ship there, with confidence?"

To answer the question, we take your input address and try to find a match in an authoritative database. (For the US, that's the USPS database. Most countries of the world have their own authoritative databases.) If we find a match, the address is declared valid, and if not, it is labeled invalid, meaning not deliverable by the USPS or the local postal authority. Note that some real addresses will be labeled invalid by this process, such as newly constructed buildings and locations where the occupants receive their mail at their local post office.

Added benefits of DPV

When you run addresses through the DPV process, not only do you get the assurance that the mail will arrive, but your address data is cleaned up, made complete, and standardized (which is a preliminary step for de-duplication). The output addresses will all have complete postal codes, which will speed mail processing and delivery, and potentially reduce your postage costs by making your mail eligible for bulk discounts.

What's more, delivery point-validated addresses can be enriched with supplemental data like geocodes and RDI information. And DPV levels of accuracy can be obtained for the addresses of many foreign countries.


Here at Smarty, we eat, sleep, and breathe DPV. Our services are CASS-certified, DPV-based, and Autobahn-fast—and you can try them for free.

If you have some follow-up questions, or you'd like a more human touch, feel free to talk to our bona fide, 100% real human customer support team. We employ only Grade A, non-GMO humans on our support team, and they're well versed both in our systems and in the industry in general. If you've got a question, odds are they can answer it. And if they can't, they'll point you to someone who can.