Talk:List of telephone exchanges in London

Page errors
1) The top of the page should make it clear that the list is of BT Exchanges (or Switches). There are many other Service Providers with Exchanges as big or bigger than the BT Exchanges.

2) Under 'Exchange name' Edmonton is listed as the 'London borough' of 'Haringey'. This is not correct, Edmonton is in the L.B. Enfield.

3) The hyperlink of 'Edmonton' takes you to Edmonton in Alberta (Canada), not Edmonton in London (UK) 82.34.255.140 (talk) 01:01, 11 February 2011 (UTC)

What is an OLO code?
78.146.21.202 (talk) 13:48, 2 January 2012 (UTC)


 * Other Licensed Operator — a landline provider that is not BT. — 91.85.38.175 (talk) 18:48, 8 January 2013 (UTC)

Issue with the trailing zero
I see an issue with adding the trailing zero in front of these numbers (020 instead of 20 for example).

This zero is the trailing number used to identify a distance call within the country/region where the dialler is located. For example, within the UK I would dial 020X YYYYYYY to reach a number in London. However if I am dialling from abroad to a number in the UK, I would have to remove the trailing zero (+44 20X YYYYYYY).

Therefore the zero is not really a constant in the phone numbers, but a preceding "code" for the PBX network to understand what I am trying to reach. One might assume that it is implicit that the zero might be optional but that is an incorrect assumption, since there are regions in the world where the trailing digit (in this case, zero), is used REGARDLESS is the number is being dialled locally or from abroad. Examples include Italy and Belgium (which are in a Closed Dialling Plan). For more information see Area code. --Pinnecco (talk) 19:07, 13 February 2012 (UTC)


 * There is no "trailing zero" but there is a LEADING zero. This is the "trunk code". You're correct that it is not dialled from abroad. However, London numbers are not now, and never have been, 020X YYY YYYY or +44 20X YYY YYYY format. London numbers are (020)  XXXX YYYY or +44  20  XXXX YYYY, where the four XXXX digits identify the exchange or provider. London landline numbers are dialled as XXXX YYYY from other London landlines, omitting the 020 area code. Presently the first X is 3, 7 or 8 only. The other digits, 2, 4, 5 and 6 for the first X are reserved for future expansion. - 79.67.243.171 (talk) 09:15, 4 January 2013 (UTC)

The list of names is far from complete
Other names I immediately remember include: ABBey [in Westminster, named after Westminster Abbey] -- famously, the London Transport Enquiry line was ABBey [ie 222] 1234, which translates to 020 7222 1234, which TfL still use, I forget what for.

LIBerty [in Merton, named after Lord Nelson, whose mistress lived at Merton Hall]. The locals wanted to call it VICtory, after his ship, but since that clashed with VICtoria, the man at Post Office Telephones [now BT] whose job it was to adjudicate/impose exchange names, [yes, according to my dad, who worked for them at the time that exchange was built, that was a formal part of one person's job description] chose LIBerty [ie 542], now 020 8532

OVAl [south of Vauxhall, named after the cricket ground] -- OVAl [ie 782], now 020 7782

Is there a fuller list somewhere online? The change to ignoring the names and just using the numbers came in IIRC the late 1960s, because most valid names had been used, and new mnemonics were becoming rather forced. I think there were by then around 2 pages of names, formatted with 2 columns each, in an approx A5-sized booklet of national dialling codes, so perhaps 200 in all, but that memory is rather hazy. Since they were all nominal 10,000 line exchanges, that would equate to max 2 million dialable numbers, which feels about right for that time.

Even once the names had been deprecated, BT's building were building new exchanges too slowly -- In Brixton in 1982 and in Clerkenwell in 1984, I had to wait months to get a phone line installed, in the first case until a new exchange had been built, and in the second, until another subscriber surrendered their line -- with the madness of the time, if you had a landline phone and moved out without requesting a name change to whoever was moving in, that number was taken back and assigned to the person at the top of the waiting list, leaving your successor with a physical line but no way of using it! That doesn't seem so odd now, when we're used to things being virtual, and "flood wiring" being installed (but not terminated) to cover possible future uses, but in the 80s it seemed ridiculous. Enginear (talk) 00:55, 29 May 2023 (UTC)