What is the Postcode Address File?
The Postcode Address File, or PAF, is the address dataset Royal Mail maintains for the UK. It lists every known delivery point, meaning any premise with a letter box or a business mailing inbox, and every UK postcode.
What is in PAF?
| Record type | Count |
|---|---|
| Residential and business addresses | 32 million |
| UK postcodes | 1.8 million |
Royal Mail publishes the current counts on poweredbypaf.com. Each address is broken into its addressing components: building number, thoroughfare, dependent locality, post town and postcode. Our PAF data documentation describes every field available through the Ideal Postcodes API.
How often is PAF updated?
Continuously. Royal Mail applies 2,500 to 3,000 updates a day. New builds, subdivided properties and demolitions all reach PAF this way, which is why an address you cannot find today may appear next month. Our guide on a missing address covers what to do in the meantime.
Why use PAF?
Because it is the dataset the postal network itself delivers against. Validating against PAF at the point of capture means:
- Customers select an address instead of typing it, so the form is quicker and the data is clean
- Deliveries reach the right door first time
- Fewer returns to process, and fewer support tickets about them
PAF drops into point of sale terminals, CRMs and any internal or customer-facing application.
How do you get access to PAF?
Commercial use of PAF requires a licence from Royal Mail. Most businesses take that licence through a solution provider rather than holding a direct feed, because the raw file needs matching, indexing and daily ingestion to be useful in a form.
Ideal Postcodes licenses PAF and serves it through Postcode Lookup, Address Finder and the API, with a UPRN and rooftop coordinates on every result. Small charities qualify for reduced-cost licensing. Get in touch if you want to talk through which licence applies to you.