# AddressValid

> Address validation explained: postal formats by country, postcode rules, checkout validation, address APIs compared and cleaning customer data. With a free format checker.

- [UK Address Format: Line Order, Post Town and Postcode](https://address-valid.com/address-formats/uk-address-format/): A UK address runs from the most specific element to the least: name, building or flat, house number and street, locality if needed, post town in capitals, then the postcode alone on the last line. The county is optional. When mailing from abroad, add UNITED KINGDOM as a final line below the postcode.
- [US Address Format: The USPS Standard, Line by Line](https://address-valid.com/address-formats/us-address-format/): A US address has three lines: recipient, delivery address line with number, street, suffix and any unit (APT 4B, STE 201), and a last line with city, two-letter state and ZIP Code. USPS prefers capitals, a uniform left margin and no punctuation except the hyphen in a ZIP+4.
- [Address Line 2: What Goes There and What Doesn't](https://address-valid.com/address-formats/address-line-2/): Address line 2 holds whatever narrows the street address down to your door: apartment, suite, unit, floor, room or building name, sometimes a c/o name. It is optional. If you live in a house with its own number, leave it empty. The street number and name always belong in address line 1.
- [German Address Format: Street First, Postcode Before City](https://address-valid.com/address-formats/german-address-format/): A German address puts the house number after the street name and the five-digit postcode before the city: name, Musterstraße 12, 10115 Berlin. There is no comma and no blank line. From abroad, add GERMANY in capitals as the last line and never write D- or DE- in front of the postcode.
- [How to Address International Mail So It Arrives](https://address-valid.com/address-formats/international-address-format/): Write the address in the destination country's own format, with the city and postcode where that country expects them, the city in capitals, and the country name spelled out in capitals alone on the last line. Never put a country code like DE- or F- in front of the postcode, and keep the block to six lines.
- [How to Verify an Address: Format, Existence, Occupant](https://address-valid.com/validation/verify-an-address/): To verify an address, check it at three levels. First the format: postcode pattern, house number, line order. Then existence: match it against postal data, for example with the USPS ZIP Code lookup or an address validation API. Finally the occupant, if it matters, with a document or a letter that must be answered.
- [Postcode Regex: Tested Patterns for UK, US, CA, DE, NL, IE](https://address-valid.com/validation/postcode-regex/): A postcode regex should check one country's pattern on input that has been trimmed, uppercased and given its standard spacing. For the UK that means six outward-code shapes plus GIR 0AA; for the US five digits with an optional hyphen and four more. A regex confirms the shape only, never that the postcode exists.
- [Address Autocomplete in Checkout: Setup and Pitfalls](https://address-valid.com/validation/address-autocomplete-checkout/): Address autocomplete in checkout suggests complete addresses as the customer types and fills the form fields on selection. Set the standard autocomplete tokens so browser autofill works, add a suggestion service on the first address line, keep the unit field visible, and always allow manual entry when the address is not in the list.
- [Address Validation API: How to Choose and What to Test](https://address-valid.com/validation/address-validation-api/): An address validation API takes an address, matches it against postal or commercial reference data and returns a standardized version with a verdict: how precisely it matched, which parts were corrected or inferred, and whether the address looks deliverable. Choose by coverage of your countries, unit-level accuracy, price at your volume and data handling terms.
- [Address Correction Fee: What UPS Charges in 2026](https://address-valid.com/data-quality/address-correction-fee/): An address correction fee is what a carrier bills the shipper when a package carries a wrong or incomplete address and the carrier finds the right one. UPS charges 25.25 US dollars per package on US Ground and Air shipments in 2026, capped at 175.25 dollars per shipment. Validating addresses before printing labels avoids most of these charges.
- [National Change of Address (NCOA): How List Updates Work](https://address-valid.com/data-quality/national-change-of-address/): National Change of Address (NCOA) is the USPS file of permanent change-of-address requests, about 160 million records. Mailers do not get the file itself; they run their lists through licensed NCOALink providers, who return new addresses for people and businesses that moved within the last 18 or 48 months, depending on the licence.
- [Address Deduplication: Finding Duplicate Customer Records](https://address-valid.com/data-quality/address-deduplication/): Address deduplication finds records that describe the same delivery point or the same customer despite different spelling. Normalise first (case, abbreviations, punctuation, spacing), build a match key, compare candidates only within the same postcode, review borderline pairs, and merge with clear rules about which record's fields win.

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