Address validation that catches the typo before the parcel ships.

Each address is split into its parts (street number, street name, unit, city, state, and ZIP or postal code), checked against postal reference data, corrected where the data allows, and returned in a standard format with a status. US addresses are processed with USPS CASS Certified software supplied by a USPS licensee. Address validation covers 240+ countries and territories with the same API key. You can run the check in real time from a checkout or signup form, or on a whole file by CSV upload.

Every address comes back standardized and split into fields you can store, with a status: valid as entered, valid after a correction, corrected without full certainty, or not valid. A detail code explains what was wrong, for example an unknown street, a street number out of range, or a postal code that does not match the city. A common pattern is to accept valid addresses, save the corrected version when DQVerify fixed something, ask the customer to confirm an uncertain correction, and ask for a new address when it is not valid. The full list of codes is in the help center.

Yes. US addresses are processed with USPS CASS Certified software supplied by a USPS licensee. CASS is a US-only standard, so it applies to US addresses only. Addresses in other countries and territories are checked against licensed postal authority data with the same API key.

No. Send the address to the address endpoint with your API key and the result comes back in under 150 ms at the 95th percentile, fast enough to check it before the customer places the order. When DQVerify corrects something, show the corrected address and let the customer confirm it. The same API key works for the email and phone endpoints, so one integration can check all three fields. Code samples for curl, Node.js, and Python are on the developers page.

Yes. Upload a CSV or spreadsheet in the DQVerify dashboard and map the address columns. DQVerify runs the same check as the API and returns a file with the standardized address and a status on every row. Files under 50,000 rows typically finish in under ten minutes. We don't store your validation data: download your results during your session, because batch files and results are deleted afterwards. The 1,000 free credits you get at signup work for file uploads too, so you can test a sample of your own list first. That's 1,000 instead of the usual 100, for sign-ups until Nov 30, 2026.

Each address check uses one credit. Sign up with a business email and you get 1,000 free credits for 14 days, with no credit card required. That's 1,000 instead of the usual 100, for sign-ups until Nov 30, 2026. After that, you buy one-time credit packs priced by check type, region, and volume. Paid credits are valid for 12 months, with no subscription and no auto-renewal. Checking the address, email, and phone of one customer uses three credits. The pricing page shows the exact price for address checks at your volume.