2026-09-05

Address verification: formats, boxes, registers and postcodes

POST /api/v1/address reads a postal address against its own country's format, names the delivery point behind it, checks the postcode against the national directory, follows the building into the national address register and counts the companies at it — all from open, licence-clean data.

POST /api/v1/address answers 45 fields: the address split into the parts its country writes, the country's facts, the address rendered the way that operator writes it, postal_code_valid and postal_code_type, postcode_status and locality_matches_postcode from the national postcode directory, address_type with the source that settled it, exists and match_level from the national address register with the coverage its publisher claims, the postcode centroid, companies_registered, is_mail_drop with the source that decided it, and a recomputable risk_score with its risk_signals. The full guide is at /docs/address-verification, and the product page at /products/address-verification has a live demo.
Send one written address or the separated fields, always with a country — the postal format is what the address is measured against, so a country the format table does not cover is refused rather than answered. Nine typed reasons say what is wrong, and every one of them is free.
address_type reads the postal operators' own naming in 52 countries: post-office boxes, private mailboxes at mail-receiving agencies, general delivery, rural routes, military mail, parcel lockers, and the business-volume arrangements that replace a street address such as the French CEDEX and the Dutch Antwoordnummer. A box replaces the street line; a private mailbox keeps it and moves its number into unit.
The data is free and licence-clean: postal formats for 206 countries (MIT), the national address registers of the United States (public domain), France (Licence Ouverte 2.0), Switzerland (© swisstopo), Austria, Czechia and Norway (CC BY 4.0), the ONS Postcode Directory for Great Britain (Open Government Licence v3.0 — Northern Ireland postcodes are excluded because their reuse needs a separate Land & Property Services licence), Companies House free company data and the Colorado, New York and Oregon business registries, and the branch lists mailbox operators publish themselves. The footer carries every attribution the licences ask for, and the status page lists each dataset with its sync date.
exists is deliberately cautious. It is true only on a building match, and false only when the register that answered claims to list every address. Where coverage is partial — the United States and France, whose registers are fed by whoever chose to take part — an address that is not in it answers null, and the not_in_register weight never applies. Absence from a partial register is not evidence that an address does not exist.
Two answers stay licensed and are not enabled: whether post is actually delivered to an address, with the postal service's own agency, vacant and residential flags, and which addresses sit at a UK postcode — every full UK address list derives from the Royal Mail Postcode Address File. The first answers deliverability_checked: false, the second answers 501 ADDRESS_LIST_UNAVAILABLE, and neither is charged or guessed. Their fields and billing are fixed now so nothing changes for your client when a partner is signed.
POST /api/v1/address/batch takes up to 100 addresses, POST /api/v1/address/public validates from a page with a publishable key, and the MCP server gained verify-address. The dashboard's new Address verification tab runs a single lookup written or as separated fields and shows every field, with "not evaluated" where a dataset is not installed.
Billing follows the same rules as the rest: 1 credit for a fresh answer that stands as written, nothing for one that cannot, and nothing for a repeat within seven days — the repeat marker is keyed on the folded address, so two spellings of one address are one lookup and one charge.
Nothing in the response says who lives or works at an address. The product is about places, and no field will ever be about people.

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