How do I tell if this address is real?

Addresses are funny things. They're kind of like Schrödinger's cat*—it's impossible to tell if they’re real or not real without checking. Luckily, checking whether an address is real doesn't require any radioactive materials (so put your Geiger counter down).

It's a method called "address validation", though sometimes it goes by other names (address verification, CASS processing, etc.), and it's what we do here at Smarty. Basically, we take the info in the USPS database, other official databases, and similar records kept in other countries, and offer it to you via a user-friendly interface. So if you're looking to double-check an address, you've come to the right place.

*No cats were harmed in the making of this article.

Address validation

Address validation is actually remarkably simple. First, countries with organized mail systems keep records of who they have signed up to receive mail. You sign up with them when you want to start getting mail. That record, usually maintained by a government organization (the United States Postal Service, for example), is the most authoritative, reliable, and up-to-date record available.

That record is where it all starts. It serves as a data point that can be used as a reference to verify whether an address is real.

Many address validation services stop there. Not Smarty! Even though the USPS database represents the most authoritative set of addresses in the US, they’re still lacking something. 

That something is millions of addresses. Since the USPS only keeps records of places they deliver to, there are still millions of addresses in rural areas where delivery isn't available. That's why Smarty starts with USPS data and then finds millions of additional addresses by combining authoritative public and private sources to give you much more.

The act of comparing an address against the database to verify its validity is called "address validation," as mentioned above. It's kind of like asking a postman if he delivers mail to a particular address, except it's a lot faster. Using APIs and specialized programs, address validation companies compare the addresses you provide to the relevant database. If there's a match, the system you're using will notify you that the address is valid. If not, you're given a thumbs-down to let you know that the postal service doesn't deliver mail to that location.

Reasons an address doesn't validate

At this point, it's important to note that just because a physical address is used doesn't mean it will be validated. Here are a few common reasons why an address may not validate, even if you could swear on your dead cat that it's a real place.

Not registered

If the address isn't registered with the postal service, there's no record of it in the system. Whether it's a house people just moved into or a business that just opened, the paperwork has to be completed for that address to "exist" in the database. The same logic applies to homes/businesses that are currently unoccupied, and places that have never signed up for mail.

PO Boxes

Some rural areas operate on a PO Box system rather than one tied to physical addresses. In these cases, the physical address doesn't receive mail from the postal service, and thus isn’t technically "valid." Checking the PO Boxes will score you a "valid" response, but the physical home and business addresses won’t. Even though the residents of that physical address are signed up with the postal service to receive mail, they do so using a PO Box.

The exception to this rule is places that offer both a PO Box and a physical address. As long as mail is delivered to both locations, the brick-and-mortar location will be considered valid, as will the PO Box address.

Outside service area

There's a chance the location you're trying to validate might be in an area not served by the postal service. Fortunately, Smarty doesn't rely exclusively on USPS data. We also include millions of addresses from authoritative public and private sources. Addresses like these will be marked as valid, and we’ll also let you know that the address is non-postal. Carriers like UPS and FedEx will often still deliver to these addresses.

Incorrect input

Sometimes the Problem Exists Between the Chair and the Keyboard — or PEBCAK, as the techies call it. It means you messed up. If there's a human error (a mistake in how the address is entered), it may be flagged as invalid. So double-check your work and make sure your information is correct and complete; the address isn't out of superposition yet.

So now you know . . .

Addresses can be checked for validity, and you can avoid the hassle of paying postage on mail that will just be returned to you. The process is simple, and there are a number of different providers; finding someone who fits your needs is just a matter of shopping around.

You may find that a postal service's address validation system (regardless of nationality) is difficult to use. But there are those who have already navigated the difficulties for you, and they can get you the data you need. So the next time you want to make sure an address is real, the answer is simple: Just check with an address validator, and then you'll know.

And knowing is half the battle . . . unless you're Schrödinger's cat.