Postcode lookup API
UK postcode lookup API on Royal Mail PAF data
One request with a postcode returns every deliverable address at that postcode as structured PAF fields with latitude and longitude, typically in under 50ms. Officially licensed via Royal Mail, with autocomplete and validation on the same key.
Free trial: 30 lookups a day for 30 days. No card required.
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Sub-50ms response times
Free tier, no card required
What a postcode lookup returns
Every address at the postcode, as fields your systems can use
Send a UK postcode and AddressBrain returns the full list of delivery points at that postcode from Royal Mail's Postcode Address File: houses, flats, businesses and new builds, drawn from around 32 million addresses across 1.8 million postcodes.
Each result comes back as separate fields, not one string: sub-building name, building name or number, thoroughfare, dependent locality, post town and postcode, plus latitude and longitude. Your checkout, CRM or label printer gets data it can store and route on.
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Postcode
lookup
Postcode in, addresses out. The classic UK pattern: the customer types a postcode, picks their address from the list, and the form fills itself with a validated, correctly formatted address.
Address autocomplete
For forms where a postcode-first flow does not fit, search as the customer types on a partial address or a business name and return matches from the same PAF data.
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Address validation
Check and normalise addresses you already hold, one at a time or in batch, and flag anything undeliverable before it reaches a label, a policy or a KYC check.
Data
Royal Mail PAF, officially licensed, kept current.
AddressBrain is a licensed Royal Mail PAF solution, so the licensing question sits with us rather than with you. New-build addresses are included as Royal Mail adds them, and 1.4m UK business names sit in the same index for work and click-and-collect deliveries.
Search on a postcode, a partial address or a business name.
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Sub-building, building name, thoroughfare, post town and postcode as separate fields.
Latitude and longitude on every result at no extra cost.
New-build addresses and 1.4m UK business names included.
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Performance and pricing
Sub-50ms responses. Plans from free to 33,000 lookups a month.
Typical UK response times are under 50ms from distributed, auto-scaling infrastructure, so peak trading traffic does not queue behind one database. Plans run from a free trial through nine monthly tiers, £49 for 1,000 lookups to £999 for 33,000, 4.9p down to 3.0p each, with volume pricing above that.
Monthly plans, change or cancel any month.
Overage charged per lookup, or we recommend a better plan.
Free trial: 30 lookups a day for 30 days, no card required.
Volume pricing and annual terms when you need an SLA.
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For developers
A REST API with an OpenAPI spec and a bearer token.
A single request with the postcode and your bearer token returns JSON. No SDK to install and no OAuth handshake, and because the API ships with an OpenAPI spec, any client generator or agent framework can call it as a tool. Create an account, copy the key out of the dashboard, and make the first call.
Authenticate with a single API bearer token, no OAuth handshake.
Free trial includes 30 lookups a day for 30 days. No card required.
Live usage dashboard, so you can watch spend as it happens.
Distributed, auto-scaling architecture, so peak trading traffic does not queue 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.Start with 30 free lookups a day for 30 days. 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.