Address checked. Delivery on track.

Up to 20% of packages run into delivery issues because of bad address data. Typos, missing unit numbers, and incorrect postal codes create costly problems fast.

EasyPost’s Address Verification API helps you catch and correct errors early so packages reach the right destination and customers enjoy a smoother checkout experience.

What’s the difference between address verification and address validation?

• Address verification confirms an address actually exists and can receive a delivery. Address validation confirms an address is formatted correctly. They sound interchangeable, but only one of them tells you a package will arrive.
• A validated address can still be undeliverable — correctly formatted, wrong reality. EasyPost’s Address Verification API does both: it standardizes the format and confirms the location is real and deliverable against a CASS-certified database, so you catch the errors that actually cause failed deliveries.

Ship better with EasyPost’s Address Verification API

Once integrated with our Shipping API, you automatically get access to our CASS-certified address verification at no extra cost.

Accurately validate addresses in over 240 countries and territories so you can ship confidently across borders.

Fast response times, reliable infrastructure, and high uptime keep address checks running smoothly inside your workflow.

What is an address verification API?

An address verification API checks a shipping address in real time — before a label is created — to confirm it exists, is deliverable, and is formatted to the destination country’s postal standard. It returns a corrected, standardized address or flags the specific error, so bad data never makes it onto a label.

For a shipping team, that check is the difference between catching a wrong ZIP code at checkout and paying for the reship three days later. EasyPost verifies addresses in over 240 countries and territories against a CASS-certified database, and the verification runs free with every label purchased through the Shipping API.

How it works

Submit an address

Provide full destination address: unit, street, city, state, zip, and country.

EasyPost validates the address

Our Address Verification API reviews the address, correcting or flagging it using our worldwide database.

Ship with confidence

Have peace of mind knowing that your package is headed for a valid destination.

Add address verification in minutes

Request (Python)

Response (JSON)

The API returns the address cleaned to USPS standard — uppercased, abbreviated, and completed with a ZIP+4 — with verifications.delivery.success: true confirming the address is deliverable. For full setup steps, see the address verification documentation.

How does address validation reduce failed deliveries?

Address validation reduces failed deliveries by catching the errors that cause them — typos, missing suite numbers, wrong postal codes — at the point of entry, before a package ships. Roughly one in five packages hits a delivery problem tied to bad address data; validating up front removes most of that at the source.

The savings compound at volume. Every undeliverable package is postage already spent, a reship to fund, and usually a support ticket and a refund on top of it. Validating the address before the label removes all three costs at once.

Reduce data entry errors and increase deliverability

More than half of ecommerce traffic now comes from mobile devices, which means more chances for typos and incomplete addresses at checkout. Auto-correct does not always help.

EasyPost’s address verification API helps customers enter accurate information the first time so deliveries arrive as expected and your team avoids costly reships and refunds.

Make customers happier

In a competitive ecommerce landscape, small checkout frustrations can cost you the sale. Address verification keeps the checkout process smooth and helps ensure customers get their orders without delays or confusion.

Save time

Automating address verification reduces manual cleanup for your team. Spend less time fixing rejected labels, tracking down delivery failures, and responding to frustrated customers.

Getting started is quick and easy

Take a look at our documentation and start building with one of our helper libraries (Python, PHP, Ruby, Node.js, Java, and more). Avoid month-long integrations and start verifying addresses in minutes with EasyPost.

Once your package ships, follow it with the Tracking API.