As technology improved, more services emerged. The GPO started with Jubilee Concession, installing a kiosk in all c8,000 towns with a Post Office. Acts of Parliament unified National Telephone Company/NTC and GPO services.
A UK telephone network division came pre-WW1 when NTC assets were acquired by the GPO, effectively nationalising the telephone network. With the combined staff and assets of two separate organisations, the GPO looked at equipment regulation, but WW1 put kiosk development on hold.
London’s First Telephone Box K1, 1921
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In 1921 Britain's standard kiosk K1 was introduced by Post Office. Its design was conservative so many of the phone box designs were protected by trademark registrations, held by British Telecommunications. K1, made of concrete, was not initially well-received and only limited were allowed. 14 K1 boxes remain, 7 registered by Historic England.
In 1923, two independent schemes were established to test design alternatives to K1. The Metropolitan Boroughs Standing Committee ran a competition to design a new national kiosk. Also the Birmingham Civic Society had produced independent proposals for a new national kiosk, which they submitted to the GPO. This caused the newly established Parliamentary Royal Fine Art Commission (1924) to examine questions of public service and art value. The red telephone box emerged from a design competition.
In 1921 Britain's standard kiosk K1 was introduced by Post Office. Its design was conservative so many of the phone box designs were protected by trademark registrations, held by British Telecommunications. K1, made of concrete, was not initially well-received and only limited were allowed. 14 K1 boxes remain, 7 registered by Historic England.
In 1923, two independent schemes were established to test design alternatives to K1. The Metropolitan Boroughs Standing Committee ran a competition to design a new national kiosk. Also the Birmingham Civic Society had produced independent proposals for a new national kiosk, which they submitted to the GPO. This caused the newly established Parliamentary Royal Fine Art Commission (1924) to examine questions of public service and art value. The red telephone box emerged from a design competition.
The public telephone box was designed by noted architect Sir Giles Gilbert Scott was in cast iron. Their distinctive red colour made them easily recognisable. From 1926, the kiosks displayed a prominent crown symbolising the government.
8 kiosk types were introduced by the GPO between 1926-83. The K6 was designed by Scott to mark the Silver Jubilee of King George V coronation in 1935. c60,000 examples were installed across Britain, explaining why the K6 became THE red Telephone Box. 11,000+ K6s remain. More stream-lined than the K2, the K6 was deployed widely by 1940, despite initial resistance to its red colour.
Scott’s design was like the K2, but smaller and cheaper to produce. The K6 was made of cast-iron sections, bolted together, standing on a concrete base. Its general design was a 4-sided rectangular box with a domed roof. The door was of teak, with a metal cup handle. Set into the slot was an illuminated telephone sign, with serif capital lettering on opaque glass. The pediments had a moulded Royal crown.
Motoring organisations, Automobile Association/AA and Royal Automobile Club/RAC, enjoyed the benefits of a telephone network for members in a network of sentry boxes. Because cars were expensive and were prone to breakdowns, the motoring clubs employed patrolmen men to shelter in the boxes and to provide motorists with roadside aid. The Police Service also grew a network of kiosks, allowing officers to keep contact with their station. Metropolitan Police Service introduced Police boxes in 1929.
Scott’s winning design, chosen by the Royal Fine Art Commission, featured a classical style with a dome like John Soane’s. Scott was Director of the Sir John Soane Museum at the same time he was working on the telephone box design. The kiosk was ideally to be constructed from cast-iron with a per-unit price c£40. Three kiosks were installed behind London’s National Gallery in 1925.
Without a cost-effective kiosk used nationwide, GPO reverted to K1 with larger windows and revised signage. This was an interim solution, and by 1928 the GPO commissioned Scott to produce a cheaper kiosk made of pre-cast concrete. The GPO was not content with the K2 they had been working on, so they planned a new kiosk which could incorporate a stamp machine and post box; a mini-Post Office.
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In 1929, Scott introduced K3, a similar design to the K2 but made from reinforced concrete for nation-wide use. The K3 was cheaper than the K2 but still more expensive than the K1. A rare surviving K3 kiosk can be seen at the London Zoo.
The K4 was an enlarged version of K2, designed by GPO’s Engineering Dept. In 1927 the K4 model included a post box and stamp vending machines. But only 50 K4 kiosks were produced. The GPO planned for a low cost kiosk. Introduced in 1934, K5 was a metal-faced plywood work, designed to be portable and used at exhibitions, but reached only the prototype stage.
In 1937 the Tercentenary Concession celebrated GPO's 300th anniversary and 1,000 more kiosks were installed for local authorities paying a low subscription. In 1939 a tougher version was introduced. In 1949 Royal Fine Arts Commission got re-involved, allowing rural examples in different colours. Post-war c60,000 examples lived, and of the 8 kiosk types introduced by the GPO, the K6 heritage legacy remains best.
In 1929, Scott introduced K3, a similar design to the K2 but made from reinforced concrete for nation-wide use. The K3 was cheaper than the K2 but still more expensive than the K1. A rare surviving K3 kiosk can be seen at the London Zoo.
The K4 was an enlarged version of K2, designed by GPO’s Engineering Dept. In 1927 the K4 model included a post box and stamp vending machines. But only 50 K4 kiosks were produced. The GPO planned for a low cost kiosk. Introduced in 1934, K5 was a metal-faced plywood work, designed to be portable and used at exhibitions, but reached only the prototype stage.
In 1937 the Tercentenary Concession celebrated GPO's 300th anniversary and 1,000 more kiosks were installed for local authorities paying a low subscription. In 1939 a tougher version was introduced. In 1949 Royal Fine Arts Commission got re-involved, allowing rural examples in different colours. Post-war c60,000 examples lived, and of the 8 kiosk types introduced by the GPO, the K6 heritage legacy remains best.
Post-war, the 1951 Festival of Britain was held on London’s South Bank. The Festival was a tonic to Britain then, showing the recovery from austerity. It demonstrated skills in the arts, architecture, industrial design, science and technology. And a crown motif with Queen Elizabeth II.
Lending library in unused kiosk
In 1959 the GPO invited submissions for a new kiosk from leading architects. After considering 6 experimental designs, K7 kiosks were designed by Neville Conder and installed in 1962. Ahead of its time, the K7’s use of aluminium was only adopted much later. So the GPO opted for a design by Bruce Martin; he proposed aluminium, not the trusted cast-iron. K8 kiosk arrived July 1968. 1969 predicted the end of GPOs kiosks. Since its inception, the GPO was nationalised, but as a Government Dept. By 1981 the Post Office was split into two businesses: Post Office & British Telecommunications, privatising telecommunications Ap 1984.
In a year British Telecom announced a £160 mill modernisation scheme: installing modern kiosks in the public network. But historical groups & progressive London boroughs highlighted the kiosks’ plight. Statutory protection was given to 2,000 key kiosks by English Heritage.
AA and RAC kiosks also worsened. Reliable vehicles allowed patrolmen to travel in their own vans and telephone equipment could be housed in smaller pedestals. And the Police kept in touch via personal radios. As British Telecom was left with unprofitable kiosks to maintain, the company created an Adopt a Kiosk Scheme, demonstrated the strength of local communities in preserving and maintaining their heritage. Local authorities adopted unused kiosks for £1, with the community accepting responsibility for maintenance. Organisations took these boxes for other uses eg some counties’ K6s became a community libraries after their mobile library services discontinued. Or a defibrillator.
Defibrillator in unused kiosk
The iconic design of the red telephone box found a place in parts of the world, eg U.S, Australia, New Zealand, where they have been preserved in historic sites. But the red telephone box is a beloved symbol of British heritage and their cultural significance endures. The red telephone box is an artwork, history and national identity, one of UK's favourite design icons in 2006!
Thank you to The Historic England Blog which you may enjoy reading.



















