What is PAF and why is it vital to UK businesses?

The Postcode Address File, or PAF, is the UK’s definitive address database. Owned and maintained by the Royal Mail, the data is updated every day, as approximately 90,000 postal workers go about their deliveries and make note of any changes. These daily updates, which Fetchify include automatically in our address search and validation databases, will involve newly built houses, demolished houses, older buildings split into multiple homes or offices, etc. 


The first PAF database, containing every residential and business address in the UK, was put together in the 1980s. Although the address information was being collected digitally, the filing system was still on paper, making updates a laborious and infrequent process. Of course, as technology has advanced, the system has been steadily upgraded and these days, the Royal Mail gathers and disseminates 4-5,000 data updates every day. In recent years, the biggest change to PAF has been a collaboration with the British Forces Post Office to reformat BFPO addresses to match the standard PAF address layout, and to include these addresses in the PAF dataset. 


Why is PAF important? Gathering accurate customer data is vital to so many businesses, whether ecommerce, government organisation, financial services, etc. An inaccurate address can mean your deliveries go missing, a bill could go to the wrong house, you could waste money on paper marketing that doesn’t find its target. Any of these, or a plethora of other issues, will cost your business time in fixing the problem and speaking with angry customers on the phone, money in lost goods, lost packaging and wasted postage, and ultimately, lost customer loyalty. With Fetchify’s simple address lookup and validation API, you can avoid these pains before they even happen. 


Our API allows you to search for any UK address by typing in just a few characters. There are two different PAF-powered options for finding and validating UK addresses: Postcode Lookup and Address Auto-Complete. How do they work? 

 

With UK Postcode Lookup you type in the postcode and then select the correct address from the drop-down menu.


Address Auto-Complete is our global address search and validation solution and PAF is only one of many different data sources that we use. With Address Auto-Complete, you can start typing from any point in the address, whether street name or postal code. The type-ahead address search tool delivers address results from as little as four characters. Simply select the correct address when it appears. Another benefit to Address Auto-Complete is that you can find the right address even if you don’t know the postcode, for example when sending a gift.   


The Postcode Address File lists every deliverable point in the UK. For buildings that are subdivided into multiple homes or businesses which share a single letterbox, PAF can be enhanced by Multiple Residence data from the Royal Mail. The Mutiple Residence Enriched dataset is available as an addition to the Address Auto-Complete search. If you think this additional data could be useful for your business, get in touch at support@fetchify.com and our team will be happy to help. 


Our best in class address lookup and validation API, uses the most up to date and definitive UK and international data sources. This simple addition to your checkout increases conversion rates by substantially reducing the hassle of long forms, increasing your customer’s trust in your website and providing a smoother user experience. The validated address data also reduces failed deliveries caused by customer errors, saving you time and money, providing exceptional return on investment, and making sure you reach the right address every time.

About Fetchify


Fetchify’s address lookup and data validation platforms cover more than 250 countries, and increases customer conversion with the fastest, most accurate customer data capture. Fetchify’s flagship products – Address Auto Complete and Postcode Lookup – reduce friction at the checkout, and also significantly increase the number of successful deliveries. Founded in 2008, Fetchify processes millions of data transactions every day for clients ranging from startups to established high-street names, and offers a full suite of data validation tools, including phone, email and bank, too.

Photo of fields and countryside with Fetchify traditional, postal and ceremonial counties
By Fiona Paton October 27, 2025
Counties are one of those quiet curiosities of UK addressing - the kind of data field that often sparks more debate than you’d expect. Should they be included? Which kind? And do we even need them anymore? As with so many things in data, the answer is: it depends. Three Counties, One Country In the UK, the word “county” doesn’t describe one single thing. It describes at least three - each with its own history, purpose, and quirk: Postal counties were once the backbone of the Royal Mail’s sorting system. They helped machines (and people) get mail to the right place efficiently. But in 1996, Royal Mail officially dropped them, and by 2010, county data was removed from the official address dataset entirely. For the postal system, counties simply no longer exist. Traditional (or historic) counties trace their origins back centuries — the counties of record, land, and local identity. They don’t match today’s administrative borders, but they persist in cultural memory and local pride. To some, these are the real counties of England. Ceremonial counties , meanwhile, are what most modern maps and local authorities recognise today. They loosely align with lieutenancy areas — the basis for everything from local government to BBC weather maps. And just to add another layer, the UK also has metropolitan and non-metropolitan counties used for administration, because nothing in British geography would be complete without a little complexity. So… Do We Still Need Them? For Royal Mail, the answer is simple: no. County names are ignored by modern sorting systems, and they don’t affect delivery. But in the real world of databases, integrations, and overlapping address systems, the answer is less clear-cut. Counties still appear because: Some legacy systems require a county field for validation. Some organisations and couriers still use them for regional routing. And sometimes, humans just like them — they help people orient themselves, especially in places with duplicate town names. It’s a reminder that addresses aren’t just for machines. They’re for people, too — and people often bring context, emotion, and memory into their sense of “place.” The Bigger Picture: One World, Many Formats  Counties are just one example of how geography, history, and technology collide in addressing. Every country — sometimes every region — does it differently. Some use regions, provinces, or prefectures. Some rely on hierarchies of towns and municipalities. Others have no subdivisions at all. For global platforms and data validation providers, that diversity creates a fascinating challenge: how do you standardise something that isn’t standard anywhere? It’s the quiet work of address intelligence — understanding not just where something is, but how people describe it. Why This Matters The goal of address accuracy isn’t to erase local identity or force uniformity; it’s to understand and support variation intelligently. Whether you’re sending a parcel, mapping customer data, or building systems that work across borders, knowing how and why these differences exist is part of getting the data right. So next time you’re faced with that little “County” field — think of it not as a relic, but as a reminder. Behind every address is a history, a structure, and a story. And understanding that story is where true data quality begins.
A man with glasses in his office is looking at his laptop with excitement.
By Fiona Paton October 27, 2025
Fetchify is delighted to announce that we have enhanced our product portfolio with the launch of our data cleansing services designed to help companies remain compliant with the General Data Protection Regulation (GDPR), maintain accurate customer addresses, and limit financial and reputational losses resulting from lost parcels. Royal Mail’s Postcode Address File (PAF) sees over 1,000,000 changes to address data each year. Against the backdrop of GDPR regulations, which stipulate that customer data must be kept up to date, there is increasing pressure on organisations to maintain an accurate picture of their customer database at all times. Businesses failing to comply face fines of up to £17.5 million or four per cent of global annual turnover. Furthermore, with UK businesses losing an estimated £1.6 billion each year due to lost or undelivered parcels, and 50 per cent of customers abandoning a brand after one poor delivery experience, the stakes are increasingly high when it comes to maintaining accurate address details. Data Cleansing tackles this by checking the addresses companies have on file against the PAF, ensuring that every matched address is complete. Not only does the report help businesses maintain accurate records continually, but it also fills in missing details, such as street information and postcodes, and standardises entries to Royal Mail’s specific formatting. Fetchify’s latest service is expected to help retailers stay on top of their GDPR obligations, minimise failed deliveries, cut returns costs, and improve the customer experience. John Griffiths, Account Manager at Fetchify, comments: “Duplicate records cause confusion, missing data undermines marketing efforts, and incorrect formats lead to delivery and communication errors. Perhaps more compelling is the fact that businesses are legally required to maintain accurate details, so it’s imperative that they get it right. Data Cleansing will address all of these issues whilst streamlining the operational efficiency of companies that use it.”
Tracey is sitting in an office environment
By Fiona Paton September 8, 2025
A spotlight on Tracey Moir, Senior Business Development Manager at Fetchify
Showroom display of a range of prams for sale at Winstanleys Pramworld
By Fiona Paton September 1, 2025
“We’ve stayed with Fetchify for over 12 years because their UK Postcode Lookup service has consistently delivered on reliability. The ease of integration, straightforward testing, and the support of a dedicated account manager have all contributed to a seamless experience that continues to meet our needs.” – David Winstanley, Director at Winstanleys Pramworld
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