Every British postcode opens with a letter, and those letters are nothing like evenly shared. We counted the first character of all 1.8 million postcodes to build the full alphabet of Britain, from the letter that carries a quarter of a million addresses to the one that barely scrapes six hundred.
The heavyweights
| Letter | Postcodes | Districts | Carrying, among others |
|---|---|---|---|
| S | 238,668 | 352 | Sheffield, Swansea, Southampton, Sunderland, all of south west London |
| B | 223,184 | 340 | Birmingham, Bristol, Bradford, Brighton, Bolton, Belfast |
| C | 155,083 | 236 | Cardiff, Coventry, Cambridge, Chester, Carlisle |
| N | 152,216 | 206 | Newcastle, Nottingham, Norwich, north London |
| L | 117,879 | 226 | Liverpool, Leeds, Leicester, Luton |
S wins the alphabet. Between Sheffield's own S area, the two Sxx blocks of south London and a string of S-towns from Swansea to Stevenage, the letter fronts 238,668 postcodes across 352 districts. B runs it close thanks to Birmingham and a remarkable roll call of B-cities. Between them, the top five letters carry nearly half the postcodes in the country.
The lightweights
At the foot of the table things get properly obscure. U fronts just 7,323 postcodes, every one of them in Uxbridge's UB area. J manages 3,393, all in Jersey. And in last place sits Z with 661 postcodes, existing only for ZE, the Shetland Islands. If you meet someone whose postcode starts with Z, they live further north than Moscow.
Y (York and the YO coast) and F (Blackpool's FY plus Falkirk's FK) are the only other letters below twenty thousand. The letter O owes almost everything to Oldham and Oxford, and A to Aberdeen and St Albans.
The letters that never made it
Three letters have never started a British postcode: Q, V and X. The designers of the system left them out deliberately in the 1960s, judging them too easy to misread in handwritten addresses. Our data confirms the rule holds perfectly across every live postcode. X does sneak into the system elsewhere, but only in special codes rather than on anyone's front door.
So the postcode alphabet runs to 23 letters, and it maps the country's urban history with odd precision. The big letters are big because Victorian cities were big. The small ones are small because, in the end, somebody had to take Shetland.
How we worked it out
We grouped all 1.8 million live postcodes in our database by first character and counted postcodes and distinct districts for each. Letters group multiple postcode areas: S includes the S, SA, SE, SG, SK, SL, SM, SN, SO, SP, SR, SS, ST, SW and SY areas, which is why its numbers dwarf any single city. Browse every area from the UK overview page.