UK address validation for banks, lenders and trading platforms
Get the address right at onboarding, not at the KYC check
AddressBrain adds Royal Mail-licensed address autocomplete and validation to your onboarding and application flows. Users pick their address in three keystrokes, and what reaches your compliance checks is a real, correctly formatted PAF address.
500 free lookups. No card required.
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Sub-50ms response times
Free tier, no card required
The cost of a free-text address field
One bad address, and every system downstream inherits it
A free-text address field accepts whatever gets typed into it. The record saves, the sign-up completes, and nothing in your logs says anything is wrong.
The problem surfaces later in whichever system is least forgiving: the identity check that doesn’t match, the card that comes back undelivered, or the payment message that fails validation. By then, the string is already in your database, and the clean-up falls on your engineers.
The address field is where the form loses momentum
Autofill for address fields increases form completion by 25% and reduces time to complete by 30%. On a regulated sign-up flow, that’s the cheapest friction you will ever remove.
A bad address does not fail without consequences
It becomes a failed match, a request for proof of address, a manual review, and an user who never comes back.
From November 2026, address structure is a compliance issue
The Bank of England will reject unstructured postal addresses in CHAPS, in line with SWIFT CBPR+ and the SEPA schemes. Town and country have to arrive in their own fields.
Autocomplete and address search
The address stops being the slow part of your form.
Add as-you-type completion wherever an address enters your product: account opening, card and loan applications, business account onboarding, or a change of address in-app. Three or four characters and the full, correctly formatted address drops straight into your form. There is nothing left for the user to get wrong, and nothing for your team to correct later.
Search by postcode, a partial address, or a business name.
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Returns clean, structured, PAF-formatted fields, not one long string.
1.4m UK business names included, for business account and sole trader onboarding.
Fewer boxes on screen, which matters most on mobile.
Postcode lookup and validation
Catch bad addresses before they reach a compliance check.
Not every address arrives through a form you control. Broker submissions, partner referrals, migrated customer records and legacy database rows often arrive with no validation at all. Run them through the lookup API, one record at a time or in a batch, and get a full, normalised address list back for any UK postcode before it’s used for anything.
Validates and normalises the data, one record at a time or in a batch.
Latitude, longitude and new build data included at no extra cost.
Clean the customer records you already hold before a migration or a remediation exercise.
Flag undeliverable addresses before you post a card, a PIN or a statutory notice.
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Structured address data
Town and postcode in their own fields, not one free-text line.
From November 2026, the Bank of England will reject fully unstructured postal addresses in CHAPS, in line with SWIFT CBPR+ and the SEPA schemes.
The practical fix starts upstream, at the point where you capture the address. AddressBrain hands the address back already split into PAF fields, so what lands in your database is structured from the moment you collect it, rather than a string somebody has to parse apart later.
Every lookup returns discrete PAF fields, not a single address string.
Run the records you already hold through the same API as a batch, so the back book gets the same treatment as new sign-ups.
Officially licensed Royal Mail PAF data, so the structure matches the UK postal standard.
AddressBrain handles address capture and cleansing. It does not build or send payment messages.
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Built for whoever builds your onboarding flow
One request and your developer can have this live in hours.
No sales call and no scoping session before anyone can test it. Your security review still happens on your timetable, but your developer can prove the thing works first.
Create an account, copy the key out of the dashboard, and make the first call. Here’s the whole integration.
Authenticate with a single [API key / bearer token], no OAuth handshake.
Free tier includes 500 lookups, no card required.
Live usage dashboard, so you can watch spend as it happens.
Distributed, auto-scaling architecture, so a marketing push or a rate change does not queue sign-ups behind one database.
On every plan, including free
What you get out of the box
Sub-50ms UK response times.
Full PAF-formatted address data, including new-build coverage.
Batch and single-lookup validation on the same key.
Start building in minutes
Create a free account and start returning validated UK addresses in minutes.500 free lockups, a test environment, full API docs, and support included.
No credit card required. Officially licensed by Royal Mail.
No credit card required. Officially licensed by Royal Mail.