Talk:020

Bexley Area Codes
I'm slightly confused about the area code for Bexley. I live in Bexley and my phone number starts with 01322 but the one in the table is 01332. I think my exchange is Slade Green whereas the one in the table is Dartford. Would someone be able to clear up my confusion and add any findings to the article. Diddy Didds 16:55, 25 June 2006 (UTC)


 * You are of course correct. The code should read 01322. The main exchange for that code is Dartford. MRSC 14:35, 25 June 2006 (UTC)


 * 01332 is the STD code for Derby isn't it? :) Neilius 15:29, 26 July 2006 (UTC)

were there "national dialing only" numbers in london before 020
and if so wouldn't theese have moved to 70xx xxxx, 71xx xxxx, 80xx xxxx and 81xx xxxx? —The preceding unsigned comment was added by Plugwash (talk • contribs).


 * What do you mean by "national dialling only"? EuroSong talk 09:48, 28 August 2006 (UTC)


 * No. These ranges were the ones issued between the move to 020 and the decision to issue 020 3 (which came some time later) - e.g. MRSC 19:29, 28 August 2006 (UTC)


 * Eurosong: national dialing only numbers are numbers within geographic area codes that can only be reached by dialing a complete national number (because they start with 0 or 1). They are only supposed to be used for purposes where they will never have to be dialed by a user of the system to avoid confusion.


 * What i'm trying to establish is if such numbers existed in london before the code change and if so what happened to those numbers. According to that site it appears they didn't move to 020 70xx xxxx,020 71xx xxxx ,020 80xx xxxx and 020 81xx xxxx but that still doesn't tell us if they existed and if so where they moved to Plugwash 01:24, 29 August 2006 (UTC)


 * I have never heard of any such numbers being issued in the UK: the concept seems rather strange. Morwen - Talk 13:43, 29 August 2006 (UTC)
 * It seems strage to me too but they are clearly mentioned in the telephone numbering plan document from Ofcom. Plugwash 14:11, 1 July 2007 (UTC)
 * They did not exist before that time. 020 0xxx xxxx and 020 1xxx xxxx are a new thing. There were no prior 0171 0xx xxxx or 0181 0xx xxxx or 0171 1xx xxxx or 0181 1xx xxxx numbers before. (79.73.128.99 (talk) 13:53, 3 June 2009 (UTC))
 * They wouldn't move to 70xx xxxx, 71xx xxxx, 80xx xxxx, 81xx xxxx, because the whole point is that NDO numbers in the (020) area BEGIN with 0xxx xxxx or 1xxx xxxx. They DID exist as 0171-0xx-xxxx and 0171-1xx-xxxx and as 0181-0xx-xxxx and 0181-1xx-xxxx numbers, and they were migrated to new (020) 0axx xxxx and (020) 1axx xxxx numbers, where a is mostly 0 or 1 so far. In fact, this type of migration happened for EVERY (02x) area code affected by the Big Number Change, and by every (011x) area code affected by PhONEday. (79.73.158.133 (talk) 21:59, 7 October 2009 (UTC))

== Need to think about this from a technology viewpoint. Historically, number ranges (I use 4 digits as an example) went from 2000 - 9989. This is because the 1 level was used for 100 (operator) and various special services and 999 was/is for Emergency services.

So, the 01 range was from 200 0000 - 998 9999 - ie 799,000 numbers. From what I can remember, if you dialled 01 from an 01 number arrangements were made to route the call back to the Director in your exchange, rather than the call uncecessarily tying up a Register in the trunk exchange.

Now what the Director did was translate the first three digits into Routing digits to route the call across London to the relevant exchange, directly or via a Tandem. It would then send out the last four digits to be "stepped out" on the destination exchange.

After sectorisation, I imagine the director in the originating exchange only had to look at the first two digits before it could route the call to the relevant Sector Switching Centre (SSC).

In this world, the three digit code had to relate to a physical exchange, where the last four digits were "stepped out". With current technology, the dial string is just a dial string, and it is easy to process all the digits. I imagine this must have become practical in the 1990s when telephone exchanges became digital, and it was trivial whether you dialled just the 7 digit local number, or included 0 and the area code, or even the international code and the area code. The microprocessors would have just dealt with it. This would make it possible to introduce 000 0000 - 199 9999 into the local number range even though dialling them without the area code would not be allowed.

[Aside: It is interesting how telephone numbers persist. We don't have e-mail numbers. ] — Preceding unsigned comment added by 82.7.53.2 (talk) 23:22, 28 December 2012 (UTC)

Map
http://www.ofcom.org.uk/telecoms/ioi/numbers/lonareacod/ex.pdf

Here is a map of the 020 code area. Notice the blatant fudge of the 0171 area so Canary Wharf and LCY get vanity central numbers. I wonder if anyone can convert into a useful map for use on here? MRSC 18:43, 20 October 2006 (UTC)

Rename
I want to rename this article as STD code is an obsolete term. I'm thinking maybe UK dial code 020. Any other suggestions? MRSC • Talk 16:43, 7 March 2007 (UTC)
 * This should be "020 (UK dialling code)". "Dial code" is not used so much in the UK. (This v. this) EuroSong talk 19:59, 24 August 2007 (UTC)
 * Heck with it, I've been bold and gone ahead with it. EuroSong talk 23:10, 24 August 2007 (UTC)
 * As you can see it has since been renamed back to just '020' and the other UK articles like 01207, 0114, etc, have also been similarly altered some time in the last few months, and at different times. (79.73.158.133 (talk) 21:59, 7 October 2009 (UTC))

Reverse directory?
Ideally, much of the content of this article needs to go. Maybe the bit about the confusion over what the code is (spotted a new "0207" board up at a construction site locally) can live somewhere, but much of this reads much like a reverse directory. Chris cheese whine 09:13, 12 March 2007 (UTC)


 * I'm not sure if it is a reverse directory. There would need to be a list of sub ranges linked to districts, and this isn't here; quite rightly as there is an element of portability now that there wasn't before which would make such a list highly dubious. The bulk of the article explains the relationship of the code to the Greater London boundary (often a source of confusion) and the rest appears to show how the code is now divided into broad sub-ranges; some mature, others reserved and some currently issued. MRSC • Talk 09:24, 12 March 2007 (UTC)


 * I'm still not seeing why we need an entire article on 020. Other than the confusion over "020x", what is there to say about it that isn't better said in geographical articles?  Chris cheese whine 09:40, 12 March 2007 (UTC)
 * PS, let's not start wikilawyering over what would or would not technically constitute a reverse directory. Chris cheese whine 09:41, 12 March 2007 (UTC)


 * Oh dear. I was just describing what I read in the article, i.e. not a reverse directory. I don't think it is unreasonable to have this article, given the complex history and my reasons above; although I am not minded to support many other UK codes (that said, there are articles for almost all the US area codes).


 * I thought wikilawyering was when folks try to use policies for questionable purposes. MRSC • Talk 10:07, 12 March 2007 (UTC)


 * The key feature of wikilawyering is arguing over insignificant technicalities, such as a precise definition of "reverse directory" ;o)  Not wanting to dwell either definition: the big table is probably better expressed as prose, and could probably be folded into Big Number Change; the "History" appears elsewhere with a rather better write-up, and much of the remainder is the sort of information that would only be of interest to the sort of people that would not be looking in a general encyclopaedia for it.  Chris cheese whine 10:43, 12 March 2007 (UTC)

ABBey and WIMbledon examples
I know what ABBey 1234 (020 7222 1234) is: the London Transport information service. But WIMbledon 1234? Could there be a better example? And in any case, most of the London exchanges (but not these two) changed in the 1960s.--Rumping (talk) 01:33, 22 April 2008 (UTC)

WHItehall 1212 for Scotland Yard is a famous one - and there was supposed to be an off-licence with the phone number WHI SKEY (SKEY = 7539). —Preceding unsigned comment added by Cardinal 1962 (talk • contribs) 16:49, 31 October 2009 (UTC)

01 Code start date?
I can see here when the 01 prefix ("If you're outside London!") ended; in 1990 - and I remember it well, but when did it start?? —Preceding unsigned comment added by Trotboy (talk • contribs) 22:49, 1 August 2008 (UTC)


 * See Telephone numbers in the United Kingdom. It was introduced with Subscriber Trunk Dialling (STD) in 1958. Sauce for this is this article. Stannered (talk) 23:43, 1 August 2008 (UTC)
 * Is that Ketchup or HP? EuroSong talk 08:55, 2 August 2008 (UTC)

History
I'm fairly confident that London all-figure numbering came in in 1969, not 1966, which I believe was the debut of subscriber trunk dialling, which originally used letters, too. My aunt was 0ES5 3019. As I understand it the problems with letters were:

The letters on UK dials were mapped differently to numbers than those abroad (principally USA, I think) and it would cause problems with international direct dialling. (Today's mapping of letters to numbers is not the same as we had in the UK up to the 1960s).

The figure 1 was not mapped to any letters, so could not be used.

Some combinations of numbers did not spell out anything pronouncable - so 777 (P, R, S) couldn't be used.

When the lettering system was dropped, people's phone numbers didn't change to the corresponding numbers - eg RIPpleway (Barking) did not become 747, but 594. The reason for this was sectorisation. The east sector (for example) with its Sector Switching Centre in Ilford had all the 3 digit codes starting 47, 50, 51, 52, 53, 55, 59 and 98. This was presumably so that the system only had to process up to that second digit to route the call to the relevant sector. In east sector this meant exchanges like LOUghton and LEYtonstone could carry on as 508 and 539 respectively. I assume the 2 digit codes were chosen to minimise the quantity of number changes

It's interesting to note that sectorisation made "pseudo area codes" a bit like 0207 and 0208. They could theoretically have made (for example) the 0147 an area code for east London and only expected people to dial the final 5 digits if they were also under 0147, but it would have been dreadfully confusing to have 8 area codes for east London! to the Ad

Also of course we had local codes from London (01) adjacent charge group. This saved on processing area codes at bigger switching centres. If the exchange in the ACG had 5 digit numbers (eg Romford for the most part) they just stuck a two digit code in front of it to make 7 digits so it looked like a local 01 number. Very clever.

I can remember RO(70)mford, and Hornchurch (HX=49) and I think Upminster was 86. —Preceding unsigned comment added by Cardinal 1962 (talk • contribs) 17:24, 31 October 2009 (UTC)

Issue with the trailing zero

 * It is a leading zero, not a 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 020 XYYY YYYY 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 20 XYYY YYYY). This is because UK adopts an open dialing plan.

Therefore the zero is not really a constant in the phone numbers, but a preceding "code" for the PSTN to understand what I am trying to reach. In fact, when dialing a number in London from London itself, we don't need to add the 020, just the remaining bits of the number. 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) 19:24, 13 February 2012 (UTC)

-- Why would anyone assue the leading zero would be optional? If you dial 20 7222 1234 from a landline in the UK you will get through to 20722 or possibly 207221 or even 207 2212 in your local area code (if that number has been allocated). The leading zero signifies that you are not dialling a local number, but a national number. It was necessary because after dialling the "0" the call would be connected to special (costly equipment that decoded the next three digits of the dial string to route the call to the correct destination exchange, and store the subsequent dialled digits for retransmission to that exchange.

A (valid) call from outside the UK would have to include the area code as the local number alone would not be unique within the UK. The 0 would therefore waste a digit in the dial string.

With modern processing capabilities I am sure +44 0xxxxxx would be acceptaable in theory, bit in the days of electromechanical switching and stored program control these constraints saved valuable equipment.

Sectors
Just a note the source cited uses "radiated from" to make clear it is segments from the centre, not surrounding circles (like the travelcard zones). MRSC (talk) 16:45, 26 September 2012 (UTC)

Capacities
Do we have any other sources beside Ofcom for the code capacities? MRSC (talk) 16:52, 26 September 2012 (UTC)

Also, the unification of 0171 and 0181 into 020 did not facilitate the numbering range of --> 10 million. The 8 digit local number facilitated that, though the numbering plan would (check) not permit an 8 digit local number after a 4 digit area code such as 0171. — Preceding unsigned comment added by 82.7.53.2 (talk) 21:35, 28 December 2012 (UTC)

Coverage
Article doesn't say what determined the size on the ground of the London Telephone Area. It is bigger than the London Postal Area. I wonder if it is connected with the planned but never implemented version of the latter? see http://en.wikipedia.org/wiki/London_postal_area#Origins — Preceding unsigned comment added by 82.7.53.2 (talk) 22:38, 28 December 2012 (UTC)

हिंदी
टेनशेन 2409:4042:2D85:13FE:0:0:A9C9:AB0D (talk) 08:36, 17 June 2022 (UTC)

Kanithan ..... social science
1277741... — Preceding unsigned comment added by 106.211.251.230 (talk) 01:47, 21 June 2022 (UTC)

capacity

 * All subscriber numbers within the area code consist of eight digits and it has capacity for approaching 100 million telephone numbers.

In NANPA no number can begin with 0 or 1, so eight digits would give at most 80 million numbers. Not so in London? —Tamfang (talk) 00:44, 4 July 2023 (UTC)

Tristan De Cunha map relevance?
Why is there is map indicating the location of Tristan De Cunha in the coverage section? 12.247.251.114 (talk) 20:47, 9 September 2023 (UTC)


 * I searched the article for the string Tristan and found this at the end of the top section: 020 is also one of the dialling codes used for telephone services on the remote South Atlantic island of Tristan da Cunha. Perhaps that explains it. —Tamfang (talk) 05:36, 14 March 2024 (UTC)