65 years since the start of the modern postcode…in Norwich

Postcodes - codes with letters and numbers. Read about the groundbreaking technology that changed the post forever.

In 1959 Norwich found itself at the forefront of a developing piece of technology that would eventually have profound and unexpected impacts on the nation…the modern postcode.

Norwich and Postal Coding leaflet cover, July 1961 (POST 110/6043)

Due to a growth in mail volumes after the Second World War, the General Post Office decided that a nationwide postal coding scheme was required to enable mail to be sorted automatically by machine.

In the early 1950s a new sorting machine was developed, sometimes referred to as ELSIE (for Electronic Letter Sorting Indicating Equipment) although SPLSM (Single Position Letter Sorting Machine) was the name that endured.

And now, from Norwich…

Norwich was chosen because it already had eight new sorting machines which were adapted so that operators could simply key in the postcode to sort letters.

Norwich Sorting Office: ELSIE – Operating position, 1960 (POST 118/16227)

The format for the postcode was a six-character alphanumeric code with three letters designating the geographical area and two numbers and a letter to identify the individual address.

The original Norwich format consisted of ‘NOR’ followed by a space, then a two-digit number (which, unlike the current format, could include a leading zero) and a single final letter (instead of the two final letters in the current format), for example, ‘NOR 09N’.

The SPLSM translated the postcode into a binary form which printed dots through phosphor tape on to the envelope. The dots were then read by a sorting machine.

Norwich and Postal Coding leaflet inside, July 1961 (POST 110/6043)

Launch Day, 28 July 1959

The Postmaster General (the government minister responsible for the Post Office) Ernest Marples came to Norwich on Tuesday 28 July 1959 to officially launch the experiment in front of the national media.

Each of the city’s 150,000 private and business addresses would receive a code by October with larger firms and businesses receiving their own individual codes. Norwich City Football Club, for instance, was assigned ‘NOR 22T’. 12 Cecil Road (the childhood home of one of Norwich’s most famous fictional sons, Alan Partridge) shared the postcode ‘NOR 78D’.

Letter from The Postmaster General announcing Norwich experiment (POST 153/292)

Ian Cameron one of two Assistant Postal Controllers involved that day tells a hilarious story about what actually happened during the demonstration of the SPLSM.

On the day itself, Norwich’s Head Postmaster John Fryer learned that one of the conveyor belts linking the SPLSM’s keyboard/printer and translator unit to the basic sorting machinery had broken. Too late to call off the demonstration they devised a trick worthy of an illusionist. There was time to run a hundred letters through the keyboard and dot-printer unit and take them out of the machine. For the demonstration, the front conveyor was operating normally. Letters were printed and went into the SPLSM.

At this point, two postmen cunningly positioned behind the machine removed these and replaced them with the pre-dotted letters for the working sorter. The audience had no idea that the letters going into the destination boxes were not the same as the ones they had witnessed starting the process. The machine’s quietness was put down to it being so cutting edge!

Post Office Magazine showing Postmaster General Ernest Marples announcing the Norwich postcode experiment, July 1959

Further problems

Although the launch itself appeared a great success, problems with the machines breaking down continued. Inevitably this technical change also wasn’t popular with all members of the public. Less than half of all letters posted bore codes.

We have a couple of postcards in the Archive sent to the Postmaster General decrying this added complication at a time when the cost of postage had increased.

Postcards from the public (POST 153/292)

National launch

Several lessons were learned from the Norwich experiment including that greater division of the last three characters of the code was needed. In October 1965, Postmaster General Tony Benn announced that postal coding was to be extended to the rest of the country in the next few years.

The eight-year programme to create a postcode for every home in the country began at Croydon in 1966. It was carried out in stages and was finally completed in 1974 with the recoding of Norwich.

Want to find out more about The Norwich Postcode Experiment? Lear more about our 2019 exhibition Sorting Britain: The Power of Postcodes.

This post was originally published in July 2019.