What is Delivery Point Validation (DPV)?

The "Fast Lane" Answer

Delivery Point Validation™ (DPV®) is the process of verifying that an address is actually deliverable, meaning that mail can be sent to that address. It checks to see if the postman would be willing to take mail to a specific location for you. A supplied address is checked against an authoritative database, and if there's a matching entry in the database, it "validates." If there's no matching address in the database, the address is "invalid," and mail cannot be shipped there.

This differs from other forms of validation and verification, which only check parts of the address. Obviously, validating the actual delivery point is more accurate than the alternatives; DPV can tell you for sure if an address is real.

Beyond that, DPV can clean up your address data, making it better for data management. And it can complete an address, speeding up processing and delivery, and potentially qualifying mail for bulk mailing discounts.

DPV is the only kind of validation we do here at SmartyStreets, so if you're looking to make sure your mail won't be returned to sender, you've come to the right place.

The "Scenic Route" Answer

Let's take a look at what DPV means, then we'll discuss how it differs from other forms of validation and, finally, what it's good for.

Point of Delivery

A delivery point is the end of the road for a piece of mail. It is the final destination for letters or packages carried by the postal service. It can be a mailbox at the curb, a PO box, or a mail slot in a front door. Basically, it's the handoff point between the mail carrier and the recipient.

Delivery points are different from street addresses; a single street address may still have multiple delivery points, such as individual units in an apartment building. To deal with this, the USPS gives each delivery point its own code—an 11-digit number that's unique to the delivery point.

The number is composed of the delivery point's 9-digit ZIP+4 Code, plus an extra two digits the public never sees (or needs to). This number is encoded into the barcode that's printed on the envelope or packaging when your mail is sorted at the post office.

Codes assigned to delivery points are not static, however. 5-digit ZIP Codes may not change very often, but ZIP+4 Codes do (monthly, in fact). This means that every month, each delivery point has a new identifier. This is likely why we're not required to know or even use the full 11-digit code: the numbers change too frequently. But there are numbers; the USPS is keeping track.


In general terms, address validation(sometimes called address verification) is when you check to see if an address is serviceable by a postal carrier. It has different variations and levels of accuracy, but the basic concept is the same. It's asking the question, "Can I ship there?" Which method of validation you use depends on how sure you want to be about the answer.

There's effectively two categories of address validation—DPV, and everything else—and understanding how valuable DPV is requires knowing how inaccurate other methods are.

Validating the Delivery Point

The process of validating a delivery point is simple. You take an address, you compare it against an authoritative database (for the US, it's the one the USPS keeps), and you look to see if the address is in the database. If it is, the address is a valid one. If not, it's invalid, and can't be confirmed as a real address.

DPV is the most reliable method of checking an address for validity. Typically, it involves standardizing, correcting, completing, and updating an address, which means your data is cleaner and more organized once it's been processed. It also means you know that the primary carrier for that location (again, that's the USPS for the United States) can and does deliver to that address, so if you ship it, it will arrive there.

It's not a foolproof system, though, because the USPS (and organizations like it throughout the world) don't deliver to every doorstep. There are a number of reason why an address might come up as invalid, and it's not all because the place doesn't exist, or the address is wrong. It could be a real, occupied location that just hasn't signed up for mail delivery yet, or has never signed up because they don't want to receive mail at their location. It could be in a rural location not serviced by the USPS, or in a location where they only deliver to PO boxes.

Whatever the case, sometimes the USPS doesn't deliver to a particular location. And sometimes carriers like UPS and FedEx do. So let's take a look at how other carriers check if an address is real.

Everything Else

Validation isn't always so precise; sometimes a different method is used to "validate an address" that doesn't check to the same level of certainty.

Take UPS as an example. They offer an address validation tool on their website, for checking to make sure that a package you ship with them will make it to the destination. How that tool works is a little more complicated than DPV. First, it will take the given address and check to see if the city/state/ZIP combination is real. If it passed that test, then the street/city combination is checked, to see if that exists within the city/state/ZIP.

Then things get funny. Instead of checking to see if the street address is real and currently receiving mail from the USPS, the UPS system checks to see if the number of the street address falls within the number ranges on that street. Take this address:

1007 Mountain Drive, Gotham

Now, let's say that all homes on Mountain Drive are assigned to the numbers between 1000 and 2000. In this case, the above address fits the possible range for addresses. If the range was instead 1500-2000, then 1007 Mountain Drive doesn't fit. If the address fits, the address is "valid" according to their system. If it doesn't fit, it's marked invalid.

In other words, the UPS system checks to see if the address is possible, rather than if it is real. It makes sense for them; UPS and private carriers like them often deliver to addresses that the USPS does not, so it doesn't matter to them if an address isn't registered with the USPS. That's why they don't check it.

But why run the risk of mailing to an address that doesn't exist? Well, since the USPS database can only tell you an address is real if it's registered with them to receive mail, and UPS wants to include in their deliveries addresses excluded by that database, they need to reference something different. So checking the address is approximated, likely with the thought in mind that the odds are slim that the house number will be wrong if everything else is right.

Here's the bottom line: companies like UPS service addresses indiscriminate of their status in the USPS database. However, they can't tell you for sure if an address is real.

Benefits of DPV

You may have already guessed, but the most obvious advantage that DPV has over other forms of validation is the assurance it gives—a valid address is real, active, and deliverable. Barring a recipient failing to pick up a package, mail delivery is nearly 100% reliable. The same can't be said of less accurate forms of validation.

But avoiding returned mail costs is not the only reason to use DPV. The standardization and address updating that happen with DPV can help you keep your data clean and organized. And there's CASS processing, which DPV is usually a part of; using CASS can help you secure bulk mail "worksharing" discounts, making your postage cheaper. It also gives you the ZIP+4 Code for your address, which can speed up delivery time, sometimes by as much as two days.

What's more, delivery point-validated addresses can be returned coupled with supplemental data for that address, like geocodes and RDI information. DPV-levels of accuracy can even be obtained in many cases in foreign countries for international address validation.

In short, you can depend on DPV.


Here at SmartyStreets, we know how cool DPV can be because we use it all the time. Our services are CASS-certified, DPV-based, and Autobahn-fast, and you can try them for free.

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

We are dedicated to providing you with the value of DPV, and once you see what it offers, you'll have a decidedly positive view of DPV too.