Norwich - The city where postcodes began
On a recent trip to Norwich, I happened upon a little blue plaque on a city building that read: “Norwich: the birthplace of the modern postcode.” Excited by this curious claim, I felt compelled to dig a little deeper - and the story I uncovered was far too fascinating not to share.
In the late 1950s, the General Post Office (now Royal Mail) sought a way to streamline the massive influx of mail processed by its new sorting machines. They needed a location with enough mail volume and mechanisation to test the system at scale, and Norwich, with its eight automatic sorting machines already in place, was chosen as the ideal candidate
The Pioneering Trial
On 28 July 1959, Postmaster General Ernest Marples officially launched the world’s first alphanumeric postal code system in Norwich. Each of the city’s roughly 150,000 addresses were assigned a unique code beginning with “NOR”, followed by a two-digit number and then a single letter - for example, NOR 12A.
This innovative format allowed machinery to quickly route mail without relying on humans reading full addresses - a breakthrough that accelerated sorting significantly.
Expansion to the Rest of the UK
Following the success in Norwich, the modern postcode system expanded beyond 1959. By October 1965, postcode trials began in Croydon, featuring the format of three inward characters - numbers plus two letters. This marked the start of a national rollout that continued through the late 1960s, culminating in full UK postcode coverage by 1974.
Why Norwich?
Norwich offered the ideal mix of scale, technology, and diversity in address formats. Its experience helped Royal Mail confirm that a code-based system could work not only in London but across the nation - a model later refined and adopted countrywide.
Why It Still Matters
- Efficiency: Machine-readable codes turned what used to be a labour-intensive, piecemeal process into a fast, reliable operation. Mail is now sorted about 20× faster than manual methods
- Ubiquity: Today, over 1.7 million postcodes span 29 million UK addresses, all thanks to Norwich’s pioneering system
- Legacy: Although formats have evolved, the concept - short, structured codes guiding sorting - originated in Norwich and reshaped communication across the UK and beyond.
A Small City with Big Impact
It’s fitting that a city of Norwich’s size - rich in history but not a global metropolis - sparked an innovation now woven into everyday life. Every time someone writes a letter or packages a parcel, they depend on a system that began here, over 60 years ago.
Postscript
Next time you jot down a postcode in your new London Letters stationery, take a moment to remember: you’re following in an innovation that started in Norwich, changed the postal world, and connects us still, season after season, letter by letter.