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The KX series of telephone kiosks in the United Kingdom was introduced by BT (British Telecom) in 1985.  The company had decided to create a newly designed and improved take on the British telephone box, which at this point consisted of only red telephone boxes.  These red boxes were considered flawed in parts by BT for several reasons, including cost, lack of ventilation, accessibility and maintenance. The sides were deliberately raised from the ground to allow for ventilation and also for the wind to blow away any rubbish dropped on the floor.

BT announced the £160 million series of new boxes, the designed by GKN, as well as announcing the eventual replacement of all existing telephone boxes.  The main telephone box in the KX range is the KX100.  The boxes were produced at a rate of 5,000 a year, with the total count of all BT-owned kiosks reaching 137,000 by 1999, a number which has since decreased by more than seventy per cent.

Due to criticism of the new design, the KX100 was replaced in 1996 by the KX+.  Rumour had it that BT stopped purchasing Kiosks in 2001, but the Payphone booth "Street Talk 6" was introduced in 2007 which effectively killed off the KX range.


KX 100
This booth was supplied with or without a door, depending on requirements. The fully enclosed version is used on sites where complete weather and acoustic protection is needed. The sides of the booth are slightly raised above ground level to prevent litter accumulation. The door has a light action and a large handle for easy opening and is wide enough to allow wheelchair access. The full length open booth is designed for use on quieter sites but still affords good weather protection and ease of access for the disabled. The KX 100 series booths can be used on single sites or suited back to back or side by side.

Height 2192, Width 890, Depth 890.
(All measurements in mm).

The first and most common KX, designed to be the direct successor to the K6, the KX100 is a four-sided rectangular box with a flat roof.  Aside from the back panel, which is formed of stainless steel panels, the three other sides of the box are made of glass, with two large window panels set above and beneath a slim, black plastic modesty panel, also with a black plastic trim around the windows.  The same three sides of the booth stop short of the ground to provide ventilation, another improvement on the non-ventilated K6, and for litter accumulation. Initial deliveries had cylindrical legs, for levelling on site, a flat-sheet roof with upturned edges and a multi-panel back.  A slightly updated model known as the Mk2 soon followed, without the adjustable legs and with a single sheet back panel and the more familiar 'biscuit tin lid' roof.

At launch, KX100s had smoked glass windows with lettering and logos printed on the inside face. To improve visibility of the kiosks - in particular during daylight hours - the printing was first moved onto the outside surface of the glass and then the smoked glass was dropped altogether.  Later kiosks were all fitted with clear glass.

The door of the kiosk has a light action and features a bright-coloured moulded plastic panel and handle for easier opening than previous boxes. For the first KX100s, this part was bright yellow, whilst the Phonecard variants used a bright green.  The payphone inside the coin-operated version was originally yellow with a blue phone, but this was later phased out.  The upper glass window panels carried the company logo, which upon launch, was the yellow dotted British Telecom 'T' logo.  Changes to the panel and handle colour and BT logo were made in 1991, changes which adorn almost all remaining KX100s.

The KX100 was designed to be supplied with or without a door, depending on requirements, with the door version designed to be located on sites where complete weather and acoustic protection is needed. The overall unit was designed to be wide enough to allow wheelchair access. The open booth is designed for use on quieter sites yet still provides good weather protection and ease of access for the disabled. They can be used on single sites or suited back to back or side by side.


Back to back KX100 Kiosks with the Pan Piper logo.

Dimensions as above.


Bilingual KX100 in Maentwrog (English and Welsh signage)


In 1996, BT, having acknowledged the negative reaction to the original KX models, made an attempt to win the public over and revisited the KX100 and built upon its design to improve its appeal and add some character.  The new updated version was named the KX+, also known as the KXplus, the KX100 Plus or the KX100+.  It is essentially an updated and taller version of the KX100.  It differs from the KX100 in that the 'waistband' in its door and sides is lower, and the colour used in the midsection trim panel and remodelled door handle also now matches the newly introduced trim panel at the top. In a nod to earlier Post Office kiosks and following the negative feedback on the KX100's design, it features a domed, plastic roof (modelled on those of the K2 and K6).  This said, the dome also brought other benefits to BT. The enhanced model was now taller and more visible than the boxes of BT's competitors, and it also offered valuable extra space for future developments, such as public wi-fi hotspot equipment. The earliest KX+ kiosks carried signage on the door and side lintels and the domed roof.  The interior of the booths are fitted with a large illuminated display panel.  They also contained a small seat and a shelf for writing or placing property.  They featured a lower handle on the door to help customers with disabilities and a new closing mechanism to make the door more robust.

The original version featured red trim panels and a red-domed roof.  This colour was chosen for its high visibility, and also to recall the red colour of the iconic Post Office kiosks.  In late 2003, BT introduced internet connectivity to select kiosks. These booths feature distinctive blue colour to distinguish them from kiosks with standard telephone equipment (see photo) and also carry the BT Openzone logo.  These kiosks have been described as perhaps "the last throw of the dice to save the telephone box", with Red Phone Box noting "the idea is good but the practicality isn't, you are unable to print out your internet findings in these boxes as a printer and paper would create mess."  The payphone within the KX+ inside takes cash, phonecards, credit cards and chargecards, with these payment options clearly written on the outside of the box rather than using red or green colour coding which was the practice of the KX series as well as elder red telephone boxes that had been updated accordingly.

The first KX+ kiosks appeared in Autumn 1996, with the first being placed in London and within its first year, over 5,000 KX+ kiosks had been installed.  Its launch also saw the end of production for the KX100. Some KX100s went on to be retrofitted with KX+ style domes - in effect a cost-reduced model, known during its development as the K Excel but supplied as KX Minus.  Both the KX+ and the KX Minus were designed by DCA and manufactured by GKN.

Introduced in 1996.

Height, 2495, Width 900, Depth 900
(all measurements in mm)

Weight 380kg


Picture to the right
KX Plus converted to a Lipton's bottle for advertising purposes.


KX 200
This design is provided as a single or double pedestal version. If s a simple, modern booth suitable for location in most street sites but can also be positioned indoors where acoustic protection is needed.

It consists of a back panel, a flat roof which also supports two glass panels which stretch down the booth but stop far short of the ground. These panels sport the BT logo.

Both housings offer ease of access for the disabled and they can be used in single sites or suited side by side or back to back.

Single Pedestal Booth - Height 2172, Width 836, Depth 640.
Double Pedestal Booth - Height 2172, Width 836, Depth 1130.
(All measurements in mm).

KX 300
The triangular design of this booth ensures good acoustic and weather protection. It enables maximum use of available floor space and gives good siting flexibility. There are two options provided, one with two glass sides, the other with one glass side and one fabricated side with acoustic panels and fittings for directory holders.

Again both housings offer slightly raised sides to prevent litter accumulation.

Several KX300s were fitted with doors that resemble the KX100 doors, although many were not.

Height 2195, Width 1190, Depth 1030, (All measurements in mm).


KX410 & 420
The KX410 and KX420 are two hooded phone booths on posts created specifically for sites with little available ground space or sites which are prone to vandalism.  As such, there is no space for directories or customer instructions, with the booth structures being made of aluminium alone, with the BT logo being on both the left and right of the structures, whilst hooded is a simple telephone.  They were also considerably shorter than the other designs.  The KX410, unlike the K420, was suitable for surface mounting.

These were not BT's first attempt at a post-situated telephone booth, as they follow the Booth No. 7A (or "Oakham" booths as they became known as) which was a yellow booth used in areas of extreme vandalism introduced some years earlier.

KX 410 - Height 1500 (above ground level), Width 570, Depth 373 - suitable for surface mounting.

KX 420 -Height 1545 (above ground level), Width 690, Depth 450 - this booth cannot be surface mounted.
(All measurements in mm)


KX410 KX420
Designed for shopping malls and such like.

This is essentially a telephone mounted to a post with two small glazed side screens to the left and right whilst topped by a hood.

A light is provided in the hood.

Available in 1996.

KX560 and KX570
For internal use, such as public walkways in shopping centres and large venues..

Similar to the KX520, but allowing for two payphones, back to back (KX560) or four payphones in a quadruple format (KX570).

All are floor mounted and have a overhead light over each payphone.  They are constructed from Stainless Steel and have toughed glass side screens.

Available in 1996.

Model Height (m) Width (m) Depth (m) Weight (kg)
KX560 2.10 0.72 1.40 192
KX570 2.10 1,40 1.40 224

KX560 to the left and KX570 to the right




Taken from many sources

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Last revised: June 02, 2023