40 years of the postcode - and it all began in Norwich
09:33 08 April 2014
There are around 1.8 million postcodes in use across the United Kingdom.
And the system – now part of everyday life, used in sat navs and lending its name to the postcode lottery – began in Norwich.
The allocation of postcodes to every town in Britain was completed in 1974, and to mark the 40th anniversary a blue plaque has been installed at Lloyds TSB in Gentlemans Walk.
This was the site of Norwich’s first post office, helping to pioneer the modern postcode.
More than half a century ago, the then Post Office had started a major mechanism programme.
This aimed to use machines to overcome the problems of labour intensive letter sorting, and depended on reducing the address to a machine-readable code.
The first postcodes were trialled in Norwich in 1959, and in 1966 the eight-year programme to postcode the whole country began.
This was completed in 1974 with the recoding of Norwich.
Steve Rooney, head of Royal Mail’s address management unit, said: “The invention of the postcode revolutionised the way post is sorted and delivered.
Postcode facts and figures
There are around 1.8 million postcodes across the UK, covering over 29 million addresses. In total, there are 48 million postcodes available under Royal Mail’s alpha-numeric system.
The combination of letters and numbers was chosen because people can remember a mixture of numbers and letters more easily than a list of numbers and it gives more code combinations.
Optical recognition machines read the postcodes and automatically convert them to phosphor dots. These are in turn read by the sorting machines which handle correctly addressed mail, post-coded letters 20 times faster than manual sorting.
On average one postcode covers 17 residential addresses.
Royal Mail’s online Postcode Finder is one of the UK’s most used webpages with around 100,000 visits a day – more than 40 million a year.
“As it has evolved, the postcode has also revolutionised the way companies do business.
“The postcode system, with origins dating back more than 150 years, continues to play an integral role in today’s technology-led world.”
The use of the postcode has evolved over the years and has found uses beyond helping to deliver post.
The postcode address file, managed by Royal Mail’s address management unit, contains details of all 29 million UK addresses.
It is used by tens of thousands of organisations and businesses every day to update databases, confirm identities, prevent fraud and support new sat-nav and location technology.
Around 90,000 postmen and women on delivery rounds look to identify any changes needed to keep the system as up to date as possible.
Almost 5,000 changes are made to the file each day – around 1.3 million a year.
The new blue plaque in Norwich to commemorate where it all began was organised by Norwich’s Heritage Economic and Regeneration Trust (HEART). Michael Loveday, chief executive of HEART, said: “We’re happy to be recognising the postcode anniversary and the unique role played by Norwich in the trial and rollout of the system.”
Royal Mail is celebrating the anniversary with a special postmark to be applied to letters from this week.
Have you got a story about postal history? Call Sam Russell on 01603 772326