Address verification is the process of confirming that a postal address genuinely exists and is deliverable by matching it against an authoritative source. In the UK that source is Royal Mail's Postcode Address File (PAF), the official record of around 31 million deliverable addresses across roughly 1.8 million postcodes. Verification answers a simple question: is this a real place that can receive mail?
What is the difference between validation and verification?
Validation checks the address is correctly formatted and structurally valid; verification confirms it actually exists and can receive post. The two are closely related, and AutoPostcode performs both in a single PAF lookup — read the companion definition of address validation for the other half of the picture.
| Term | Question it answers | Source |
|---|---|---|
| Validation | Is it correctly formatted? | PAF format rules |
| Verification | Does it really exist & deliver? | Royal Mail PAF |
| Autocomplete | Which real address did you mean? | Royal Mail PAF |
How does address verification work?
The submitted address is matched against Royal Mail PAF. If a live delivery point is found, the address is confirmed as deliverable and returned in standardised form; if no match exists, it is flagged as unverifiable so you can prompt for a correction.
- Match against ~31M authoritative PAF delivery points
- Confirm the postcode is live and correctly assigned
- Return a standardised, deliverable address
- Flag unmatched or ambiguous input for review
Why verify addresses at all?
Unverified addresses drive failed deliveries, returned post and wasted mailings. Verifying at capture removes the largest cause of these costs and keeps CRM data clean. Add it to any form with our UK address validation API.
A modern, UK-first alternative
AutoPostcode is a developer-friendly, affordable alternative to Loqate, Fetchify and Ideal Postcodes — the same Royal Mail PAF data, a faster integration and clearer pricing.
Frequently asked questions
What is address verification?
Address verification is the process of confirming that a postal address genuinely exists and is deliverable by matching it against an authoritative source — in the UK, Royal Mail's Postcode Address File (PAF), which holds around 31 million deliverable addresses across roughly 1.8 million postcodes.
What is the difference between address validation and verification?
Validation checks an address is correctly formatted and structurally valid; verification confirms the address actually exists and can receive mail. AutoPostcode performs both in a single PAF lookup.
How does address verification work?
The address is matched against Royal Mail PAF. If a matching, live delivery point is found, the address is confirmed as deliverable and returned in standardised form; if not, it is flagged as unverifiable.
Why do businesses verify addresses?
Verified addresses cut failed deliveries, returned post and wasted mailings, each of which carries a real cost. Verification also improves KYC, fraud checks and CRM data quality.
Does address verification confirm someone lives there?
No. Verification confirms the address is a real, deliverable UK delivery point in PAF. It does not confirm occupancy — that requires a separate identity or occupancy check.
Is Royal Mail PAF the best source for UK address verification?
Yes. PAF is the official, continuously updated record of every deliverable UK address, which makes it the authoritative source for verification. AutoPostcode serves it over a fast REST API.
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