Public telephony did not always take place in an illuminated, sheltered kiosk on the street. In the late 19th century, public phones were situated in hotel foyers and shops, very often with an attendant on hand in the posher establishments to contact the telephone exchange on your behalf and collect the fee. The provision of street kiosks began in the early 1900s, with each municipal authority producing its own design.

Kiosk 1 (K1)

The first standard design, K1 (Kiosk 1), hit the streets in 1921. Birmingham’s phone box was taken as the model, and although there were superficial resemblances to the iconic box, in terms of its overall dimensions, the design was quite different. K1 was mostly white, with its window panels framed in bright red, and looked a little like a miniature pagoda. On top was a free-standing, four-sided sign, with “TELEPHONE” in red on each side, topped with a four-pointed, wrought-iron corona that hinted at a chandelier.

K2: design competition

In 1923, the GPO (General Post Office) authority launched a competition to design a new standard kiosk, K2. It attracted a sizeable entry, and it was only in 1926 that the winning design was selected. Giles Gilbert Scott was already an architect of note, designer of the Liverpool Anglican Cathedral, and his phone box had all the solidity expected of the public building that it effectively was.

The kiosk was now uniformly red, a livery that matched the pillar boxes. It had the air of a sentry-box, painted in the colour of a guardsman’s tunic, an impression reinforced by the royal crest that appeared above the word “TELEPHONE”. Three of its four façades contained 18 glazing panels, and the design was topped off with a gently domed roof – the touch of aesthetic genius that was to survive successive modifications to the basic design over the decades.

K3: more economical

K2’s only flaw was that it was just too good. The costs of producing and installing it nationwide were deemed too high, and, in 1929, Giles Gilbert Scott was asked to produce a new design. A smaller, more economical concrete version, K3, was the result, and was installed throughout the country by the thousand.

K4: a post office version

The K4 was an experiment was tried in which a stamp machine and postbox were grafted on to the basic K2 box, and the kiosk rather grandly renamed "POST OFFICE". This failed to catch on.

K5: the temporary measure

K5 was a lightweight, plywood version of a public call-box intended for temporary instalment at trade fairs, exhibitions and similar events. Then came the defining moment.

K6: the one we know and love

In 1936, Giles Gilbert Scott produced a further refinement. K6 (known as the Jubilee Kiosk, because it was introduced in the year of George V’s silver jubilee) was essentially an amalgam of the good points of K2 and K3, a cast-iron, domed red box whose compactness made it cost-effective to mass-produce. In place of the 18 equally sized panes of glass on each side, it now had eight horizontal panes, with vertical glazing bars dividing them narrowly at each edge. This is the box that many of us grew up with.

The door opened fairly stiffly on a closer, so that it couldn’t be carelessly left open in bad weather. Inside was a majestic black phone with a rotary dial, its receiver attached to it with a heavy-duty cord. It was mounted next to a coinbox with two buttons, A and B. You put in the money, dialled the number and, on receiving an answer, pressed button A to release the coins into the machine and pre-pay for the call. If there was no answer you would at some point decide to give up and press button B to get your coins back.

On the wall in front of you, framed instructions for using the phone extended to surprising length, considering how essentially straightforward its operation was. There were local directories so you could look up a number without having to dial zero to speak to the operator. There may well be a couple of advertisements, and there was very often a little mirror, so that you could check that you didn’t look too dishevelled before stepping back into the outside world.

A reconstruction of an original K6 Jubilee Kiosk 1936 interior, on display at the Connected Earth gallery at Amberley Working Museum, West Sussex
©Courtesy of BT Heritage

Seventy-thousand K6s were installed in Britain’s streets. It reigned unchallenged as the public call-box until the 1960s, when incessant vandalism and the high cost of maintenance led the Post Office, and subsequently British Telecom, to commission a new generation of more accessible phone boxes. They lost their domed roofs. Then they lost their red uniforms, and finally even their doors. They were on their way to becoming little more than posts with phones attached when a conservation movement in the 1990s persuaded BT to renovate, and even re-install, some of the old K6s.

These days, phone boxes offer e-mail retrieval, broadband internet access, even cash-dispensers, but the phone itself might well be their least necessary feature. The pre-decimal tuppence you used to put in the slot is now a minimum 30p. They might be useful if your mobile battery is dead, or you haven’t bought your next top-up card yet, but the unavoidable fact is that these days we nearly all have a phone in our pockets and bags anyway.

There was a mystique to Giles Gilbert Scott’s phone box. More than just a convenience for those who needed to make a call while out and about, or for those who didn’t possess a home phone, the phone box was a place. When the door shut snugly on you, it felt like you were in another world entirely, an impression reinforced by the fact that they were fairly effectively soundproofed. And despite the fact that they were glazed on three sides, it was possible to run away with the idea that nobody could see you, so that you might get gesticulatingly angry while arguing with your bank, or, if you were 15, squeeze in there with the love of your life for the most romantically energising kiss you would ever enjoy.