Did you know that even Father Christmas has his own postcode - SAN TA1. Letters sent to this postcode DO arrive!
The combination of characters means that there are approximately 27 million postcodes in operation.
Postcode data isn't free - Royal Mail licences use of the postcode database for a charge of around £4000 per year!
The Royal mail can trace its long history back to medieval times, when Henry VIII established a Master of the Posts in 1516.
The first Royal Mail train ran on the Liverpool and Manchester Railway in 1830, with the first Mail coach running in 1784.
Britain is the only country that issues stamps without the country of issue on them, and the first to issue prepaid postage stamps.
Royal Mail appointed its first ever woman chief executive in 2012, a Canadian called Moya green, to replace Adam Crozier.
It took the GPO - now the Royal Mail - 15 years to introduce the alphanumeric postcodes to all areas of the United Kingdom.
An early form of the modern postcode system was introduced in London from 1857, which was incorporated into the modern system.
British Forces Post Office operates a system separate to the Royal Mail, allowing for delivery to British forces across the world.
Girobank's HQ in Bootle, Liverpool uses its own non-geographic postcode - GIR 0AA, separating it from the standard postcode format.
Integrated Mail Processors automatically read the postcode on mail, tranlating it into to barcodes - the inward and outward parts.