Explore by Country
Browse postcodes, towns and local information across all four nations of the United Kingdom
How UK Postcodes Work
Every UK postcode is split into two halves. The outward code narrows your location to a district, and the inward code pinpoints a specific group of addresses. Click each part below to learn more.
The Outward Code
The first half of a UK postcode (before the space) is the outward code. It tells Royal Mail which sorting office should handle the letter. The outward code is made up of the postcode area (one or two letters like "SW" or "M") and the postcode district (one or two numbers like "1A" or "26"). Together they identify one of roughly 3,000 delivery districts across the country.
For example, "SW1A" tells us we're in the South West London area, district 1A, which covers Westminster, Whitehall and Buckingham Palace.
The Inward Code
The second half (after the space) is the inward code. It always follows the same format: one number followed by two letters. The number is the postcode sector, which narrows the location to a neighbourhood within the district. The two letters form the postcode unit, identifying a specific delivery point of around 15 addresses.
Royal Mail adds approximately 2,750 new postcodes and removes around 2,500 each month as streets are built, addresses change, and delivery routes are reorganised.
The Postcode Hierarchy
The UK postcode system works like a set of nesting boxes, each level getting more precise:
Key Facts About UK Postcodes
- The UK postcode system was introduced by Royal Mail in 1959 in Norwich, and fully rolled out nationwide by 1974.
- Postcodes vary in length from 5 to 7 characters (excluding the space). The shortest format is like "M1 1AA" and the longest like "SW1A 1AA".
- The letters C, I, K, M, O and V are never used in the inward code to avoid confusion with numbers.
- Some postcodes are non-geographic, used for PO Boxes or large organisations. For example, "SW1A 2AA" is the House of Commons and "EC4Y 0HQ" is the Bank of England.
- Postcodes are used far beyond mail delivery. Insurance companies, property valuations, census data, emergency services and sat-nav systems all rely on them to pinpoint locations.
- The GIR 0AA postcode was historically assigned to the National Girobank. It is one of the few postcodes that doesn't follow the standard format.
UK Postcode Areas
Click any area to explore its postcodes, towns and local information
Browse Postcode Areas by Region
All 124 UK postcode areas arranged by region
Explore Cities & Counties
Jump straight to a major city or browse the UK's largest counties
Major Cities
Top Counties
Resources & Tools
Free calculators and lookup utilities for UK postcodes
Bulk Postcode Lookup
Look up town, county, latitude and longitude for up to 50 UK postcodes at once.
Use Tool Elevation ExplorerCompare Postcode Elevations
Compare the elevation of up to 5 UK postcodes side by side. See which is highest and by how much.
Use Tool DistanceDrive Time Calculator
Calculate driving time and distance between any two UK postcodes.
Use ToolLatest from the Blog
News, guides and insights about UK postcodes and places
The 20 Highest Settlements in England
The long-running argument over England's highest village doesn't have a tidy answer. Our elevation data for every settlement in the country throws up 20 places sitting above 400 metres — from the lead-mining hamlets of the North Pennines to the windswept streets of Dartmoor.
Read MoreFamous UK Postcodes and the Stories Behind Them
From Buckingham Palace to Coronation Street, some UK postcodes are more famous than the streets they serve. Here are the stories behind them.
Read MoreThe UK's Most and Least Dense Postcode Areas
Which parts of the UK pack the most postcodes into the smallest space? We analysed our database of 1.8 million postcodes to find out.
Read MoreFrequently Asked Questions
A UK postcode is an alphanumeric code used by Royal Mail to identify a specific geographic area for mail delivery. Each postcode typically covers around 15 addresses and consists of two parts: the outward code (e.g., SW1A) which identifies the district, and the inward code (e.g., 1AA) which narrows it down to a small group of addresses. Postcodes are used throughout the UK for everything from navigation to insurance quotes, property searches and government statistics.
Use the search bar at the top of this page to look up any UK postcode, town, street or school. You can type a full postcode like "SW1A 1AA", a partial postcode like "M1", a town name like "Manchester", or even a street name. Our search will return matching results instantly. You can also browse by country, county and town using the directory links on this page.
Each postcode page includes GPS coordinates, the administrative district, county and country it falls within, the parliamentary constituency, local authority, and electoral ward. You'll also find nearby schools with Ofsted ratings, the closest train stations with distances, nearby postcodes, and links to the surrounding town or city page which includes property price data and local demographics.
Our postcode data is refreshed regularly to reflect changes published by Royal Mail. School information is updated following Ofsted inspections and Department for Education releases. Property price data comes from HM Land Registry as new transactions are recorded. Transport data is sourced from National Rail and updated periodically.
The outcode (or outward code) is the first part of a postcode before the space, such as "SW1A" or "M1". It identifies the postcode area and district. The incode (or inward code) is the second part after the space, such as "1AA" or "4BD". It identifies the sector and delivery point within the district. Together, the outcode and incode form a complete postcode that pinpoints a precise location.
There are 124 postcode areas in the UK, each identified by one or two letters at the start of the postcode. For example, "SW" covers South West London, "M" covers Manchester, and "EH" covers Edinburgh. These areas are grouped into 12 regions including London, Scotland, Wales, Northern Ireland, and the English regions. Each postcode area contains multiple districts (like SW1, SW2) which are further divided into sectors and individual postcodes.
Yes, you can search by street name using the search bar at the top of any page. Type a street name like "Baker Street" or "Oxford Road" and our search will return matching postcodes with their full addresses. You can also combine a street name with a town (e.g., "High Street, Cambridge") for more precise results. Each street page shows all postcodes on that street along with a map and nearby amenities.
A postcode area is the broadest geographic division, identified by the first one or two letters of a postcode (e.g., "B" for Birmingham, "SW" for South West London). There are 124 areas across the UK. A postcode district is a subdivision within an area, created by adding a number (e.g., "B1", "SW1"). There are around 3,000 districts. Districts are further divided into sectors (e.g., "B1 1") and then individual postcodes (e.g., "B1 1AA"). This hierarchical system allows Royal Mail to sort and deliver mail efficiently across the country.