What Is Royal Mail PAF and Why Does It Matter for UK Deliveries?

In 2026, most UK shoppers expect to find their address in seconds at checkout - type a postcode, pick from a list, done. But the accuracy of what appears in that dropdown depends entirely on which address database sits behind it. Royal Mail PAF data is the definitive UK address dataset, and understanding what it is - and why it's licensed the way it is - helps you make a much better decision when choosing an address lookup tool for your store.

What Is the PAF Dataset for Royal Mail?

The Postcode Address File (PAF) is Royal Mail's master database of every deliverable address in the United Kingdom. It contains over 30 million addresses, structured at the individual delivery point level - meaning it knows about Flat 3B as well as the building it's in. Royal Mail maintains PAF as the authoritative record because it's the same data postal workers use to sort and deliver the post every day.

PAF isn't just a list of streets. Each record includes:

• Sub-building name and number (flat, unit, suite)
• Building name and number
• Street name and locality
• Post town and postcode
• A unique UDPRN (Unique Delivery Point Reference Number) for each address

That flat and unit-level granularity is what separates PAF from alternatives like Google Places. Google's address data is built from map data and user contributions - it's excellent for navigation, but it frequently misses sub-building detail for UK residential addresses. For a delivery, "Flat 3B, 12 Station Road" and "12 Station Road" are not the same address. TfL data from 2026 notes that delivery attempts failed 156 million times across the UK in 2021 - incomplete address capture at checkout is a meaningful contributor to that figure.

What Does PAF Mean in Royal Mail Terms?

PAF stands for Postcode Address File. Royal Mail created it and owns the intellectual property rights to it. That ownership has real legal weight - in October 2025, the High Court of England and Wales ruled that getAddress.io had infringed Royal Mail's database rights by using PAF data without a proper licence. The service shut down, leaving thousands of WooCommerce stores with broken address lookup overnight.

The lesson is straightforward: the dataset that powers your checkout's postcode lookup needs to come from a provider with a verified PAF licence. Royal Mail's own AddressNow service confirms that licensed providers must meet Royal Mail's standards for data handling and end-user terms. SnapAddress is a licensed Royal Mail PAF Solutions Provider - you can verify that status directly with Royal Mail's Address Management Unit.

How Does PAF Licensing Work in the UK?

Royal Mail licenses PAF to approved Solutions Providers, who can then offer address lookup services to end users. As a store owner or developer, you don't need a direct licence with Royal Mail - your provider's Solutions Provider agreement covers your use. But the licence does impose conditions that flow through to how the service works.

The most important condition for buyers is that licensed providers must enforce usage terms on the data they supply. That's why PAF-based credits expire - typically after 12 months. This isn't a commercial trick. It's a licensing requirement that every legitimate PAF provider operates under. If a provider offers PAF data with no expiry and no usage terms, that's a red flag about whether their licence is legitimate at all.

Understanding this also explains why providers like Loqate use annual subscription models with minimum commitments. The licensing structure requires ongoing agreements, and enterprise providers pass that complexity - and cost - directly to customers. There's a meaningful difference between subscription pricing and credit-pack pricing, and knowing the licensing context helps you evaluate those models honestly.

How Often Is PAF Updated?

Royal Mail updates PAF monthly. New builds, subdivided properties, renamed streets, and newly assigned postcodes are all reflected in the monthly release cycle. For a UK e-commerce store, this matters because the address your customer types today needs to match what a courier's routing system expects tomorrow.

SnapAddress pulls from PAF data updated monthly, so every lookup hits a current dataset. That's not a given across all providers - some cache older snapshots to reduce infrastructure costs, which introduces drift between what a customer selects at checkout and what actually exists in Royal Mail's current records.

PAF vs Other UK Address Datasets

There are a handful of address datasets used in UK lookup tools. The main alternatives to PAF are Google Places, OS AddressBase, and UPRN-linked datasets from Ordnance Survey. Each has a different primary purpose:

• Google Places - optimised for map search and navigation, not postal delivery. Sub-building detail is inconsistent for UK residential addresses.
• OS AddressBase - comprehensive for geographic and planning purposes, but not maintained as a postal delivery record.
• Royal Mail PAF - maintained specifically as a postal delivery dataset, updated monthly, with UDPRN-level granularity for every deliverable point in the UK.

For a checkout postcode lookup, the question is simple: which dataset does Royal Mail use to deliver parcels? PAF. That makes it the right data source for address capture at checkout. Baymard Institute's checkout usability research identifies address entry as one of the most friction-heavy steps in the checkout flow - using the wrong underlying data makes that problem worse, not better.

If you're evaluating address lookup tools, our full API comparison covers how PAF-licensed providers stack up against each other on data accuracy, pricing, and WooCommerce compatibility.

Why This Matters for Your WooCommerce Store

Choosing a PAF-licensed address lookup provider isn't just about data quality in the abstract. It's about whether the flat number on a customer's order actually reaches the right door, whether your provider can demonstrate a legitimate licence if Royal Mail ever asks, and whether your checkout keeps working when a provider without a proper licence faces legal action.

SnapAddress uses Royal Mail PAF data, charges from 2.5p per lookup with no subscription, and works with both classic WooCommerce checkout and the newer WooCommerce Checkout Blocks - an area where most existing address plugins break. Credits are valid for 12 months, consistent with the PAF licensing requirement every legitimate provider works under. You can start with 100 free lookups, no card required, at snapaddress.io.

Frequently Asked Questions

Why do PAF credits expire after 12 months?

Credit expiry is a Royal Mail PAF licensing requirement, not a commercial decision made by individual providers. Every licensed PAF Solutions Provider operates under Royal Mail's end-user terms, which restrict how long data can be accessed under a given agreement. An address lookup provider that offers non-expiring PAF credits should prompt questions about whether their licence is genuinely in order.

Do I need my own Royal Mail PAF licence as a store owner?

No. When you use a licensed PAF Solutions Provider like SnapAddress, your use of the address data is covered by our Solutions Provider agreement with Royal Mail. You don't need to register with Royal Mail directly or negotiate a separate licence. The provider takes on the licensing obligation; you benefit from the data.

Is Royal Mail PAF data better than Google Places for UK address lookup at checkout?

For UK postal delivery, yes - PAF is the more accurate choice. Google Places is built for map navigation and lacks consistent sub-building detail (flat numbers, unit names) for UK residential addresses. PAF is maintained specifically as a postal delivery record and is updated monthly by Royal Mail. For a checkout where the goal is a deliverable address, PAF data reduces the risk of failed deliveries caused by incomplete address capture.