UK postcodes in a radius

How to use it

Search for a place, type a postcode in “Center on a postal code” (SW1A 1AA), use your location or tap the map to set the center, then choose the radius in miles or kilometers. You can also drag the edge of the circle on the map. The list is sorted from nearest to farthest; tap a postcode to see it on the map.

Choose which codes you want: full postcodes (SW1A 1AA), sectors (SW1A 1) or districts (SW1A). “Copy the codes” gives you the list with commas or one per line, and Download CSV adds the ward, the local authority, the distance, the direction and the coordinates. The link keeps the center, the radius and your choices.

1 mile around Trafalgar Square

Within 1 mile (1.6 km) of Trafalgar Square, in central London, there are 7,213 full postcodes, making up 86 sectors and 24 districts. The closest are SW1Y 5AY, SW1Y 5BJ and WC2N 5DP. In a city center a full postcode can be a single building, so even a small radius catches many.

How a UK postcode works

It has two halves. The first, the outward code or outcode, is the area (the letters: SW is southwest London) and the district (SW1A). The second, the inward code, is the sector (the digit: SW1A 1) and the unit (the two letters: SW1A 1AA). A unit is a street or part of one, about 15 addresses on average; a sector groups about 160 units, and a district several sectors.

The data has 1,748,230 full postcodes, 10,841 sectors and 2,863 districts. The district with the most postcodes is CR0, with 2,791. Sectors are the unit Royal Mail uses for leaflet drops; districts work for bigger delivery or service areas. Full postcodes go up to a 25 km (15.5 mile) radius; beyond that the list would run to hundreds of thousands.

Where the data comes from

Postcodes and their points come from Code-Point Open, by Ordnance Survey, Britain’s mapping agency, with Royal Mail data as of July 17, 2026. It’s open data under the Open Government Licence, which allows any use with attribution. Each postcode’s point is in the building of the address closest to the middle of all the addresses in that postcode, on the British National Grid; we convert it to latitude and longitude with Ordnance Survey’s transformation (a few meters out at most).

Code-Point Open covers Great Britain only: Northern Ireland (BT) postcodes aren’t included, because their open data doesn’t allow commercial use, and neither are the Channel Islands or the Isle of Man. Postcodes with no point (business-only or brand new ones) are left out too. Postcode boundaries aren’t open data, so the list goes by one point per postcode.

The ward (a council’s electoral division) and the local authority of each postcode come in the same release, with Boundary-Line names. Attribution: Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Contains National Statistics data © Crown copyright and database right 2026.

What it’s for

Setting a delivery or service area (“we cover 10 miles”), planning a leaflet drop by sector, setting up the postcodes for an ad campaign, splitting territory between sales reps, or checking which postcodes a shipping rate covers.