UK telephone code misconceptions

Widespread UK telephone code misconceptions, in particular brought on by the Big Number Change in 2000, have been reported by regulator Ofcom since publication of a report it commissioned in 2004. A further study was commissioned in 2005 which found that only 13% of respondents correctly identified the 020 code for London without prompting: 59% incorrectly identified it as "0207" or "0208".

The telephone area code for most of Greater London and some surrounding areas is 020, not "0207", "0208" or "0203". All London telephone numbers have eight digits, most clearly expressed as two sets of four. The London number (020) 7946 0234 can be dialled as 7946 0234 from any other land-line whose area code is also 020.

Other affected area codes include Bristol, Cardiff, Coventry, Leeds, Leicester, Northern Ireland, Nottingham, Portsmouth, Reading, Sheffield and Southampton.

Background

Owing to the marked increase in demand for telephone numbers to be available for allocation since the 1990s, the United Kingdom's telephone numbering system has been restructured several times on both a national and regional level, resulting in several modifications to the way British telephone numbers are written. As a consequence of these changes, many people were left with a misunderstanding of how the system of area codes and local numbers operates.

A standard United Kingdom fixed telephone number (i.e. a landline, or geographical number, as opposed to a mobile telephone number or special rate non-geographic fixed line) is divided into three parts, the trunk prefix code (0 in the UK), an STD code (area code) followed by a local number. The STD (Subscriber Trunk Dialling) code indicates the geographical area of the number, and is dialled before the local number. For the majority of calls dialling within the same area, both the trunk prefix and area code can be omitted. Due to number capacity constraints, fixed line callers in Bournemouth, Poole and Christchurch (01202) must dial the full STD code even when calling local numbers. From October 2014, similar schemes were implemented in the following areas: Aberdeen (01224), Bradford (01274), Brighton (01273), Middlesbrough (01624) and Milton Keynes (01908). Some telephone service providers differentiate ordinary calling costs using the relevant area code(s).

Until STD was introduced, only telephone operators could connect calls over the trunks (long distance links between major exchanges). A subscriber would have to dial 0 for the operator and then request a long distance call. As STD was introduced area by area the meaning of the 0 changed, and it was now the trunk prefix used to raise a call automatically to the trunk dialling level - what the telephone companies now call a National call. The new code of 100 was introduced for calling an operator. Thus, the 0 at the start is not really part of an area code, which is why international callers dialling into the UK must not dial it.

The area code plus local number can have varying total and composite digit lengths, for historical and operational reasons, but as a rule they do not exceed 11 digits in combined length. For readability, and to distinguish geographic location, telephone numbers are often spoken, displayed and published with a gap between the area code and local number, and/or with the area code in brackets. Problems occur for the reader when this spacing or formatting is incorrectly applied by the publisher.

London numbers

History of the confusion

When the UK's original STD codes were allocated in the late 1950s, London was given the code 01. Relatively few subscribers could dial trunk calls, so the 01 code was not generally included as part of the published telephone number. In the early 1960s London telephones still had exchange names, the first three letters having to be dialled before the four-digit local number, e.g. ABBey 1234 (London Transport).

In the mid-1960s, All Figure Numbers (AFNs) were introduced in London and five other large cities because the number of meaningful letter combinations was becoming exhausted. The STD codes were incorporated as part of the AFN, ABBey 1234 becoming 01-222 1234. Callers in London were still instructed to dial only the seven digits (those after the hyphen) when calling other London numbers because an error message would result if the 01 code were dialled. This restriction was eventually phased out as exchanges were modernised, and the STD code was shown in brackets to standardise with the format used in non-AFN areas, e.g. Canterbury (0227) 234567. The term 'Area Code' also replaced 'STD Code' which had become outdated.

In May 1990 the single London area was split into two areas, because of increased demand. Inner London was given the code 071, for example, (071) 222 1234, and the rest 081. Consequently, there potentially then existed two separate numbers, because they were in different area codes, and (081) 222 1234 could also be valid. The local numbers remained as seven digits. This doubled the numbers available for London, but it also meant that a person from outer London, when calling a central London number (and vice versa), had to dial the full number including prefix. Although call charges between the adjacent areas remained at a local rate, some may have believed charges within the city increased as a result.

To free up more numbers for future use, on Easter Sunday, 16 April 1995 (dubbed "PhONEday"), an extra digit "1" was inserted after the initial zero into all except five geographical area codes nationwide, so inner and outer London became 0171 and 0181 respectively — for example (0171) 222 1234. At the same time, those five other places gained a brand new 011x area code. Reading later gained a new 011x code as available numbers quickly became scarce after PhONEday, being done in stages between 1996 and 1998.

Reunification

Further increased demand for telephone numbers in London led to the need for more number-space: rather than again split area codes, it was decided to merge the 0171 and 0181 area codes back into one but add an extra digit to the start of each London local number, thus increasing the available numbers fivefold.

From 1 June 1999, a new code for a re-united London was created, 020. All the old seven-digit numbers had a 7 or 8 prefixed to them, depending upon whether they had been part of 0171 or 0181. Thus:

(0171) xxx xxxx became (020) 7xxx xxxx
(0181) xxx xxxx became (020) 8xxx xxxx

Direct dialling of 8-digit local numbers was not implemented until 22 April 2000. After this date, London became once more fully united and all local numbers could be connected correctly from anywhere in the area. The following diagram shows the history of London's code, starting with the original unified 01 code and ending with the reunified 020 code:

Misquoting

Although London was re-united, people still frequently quote and write London numbers as if the city and surrounding suburbs were still split up into central and suburban areas by saying and writing "0207" and "0208". If the London number (020) 7222 1234 is written as 0207 222 1234, and then dialled in full, the destination will be reached. However, it is incorrect to place the pause as shown, because if the local number is dialled on a landline from within London as if it is just 222 1234 - it will not be connected because it is missing the first digit (of eight digits). On the day of the changeover, one in three callers failed to correctly use eight-digit local dialling.

Possible causes for the misunderstanding include the confusion created during the period from 1 June 1999 to 22 April 2000, where it was not possible to dial eight-digit local numbers; the fact that people had become very much accustomed to the audio rhythm of a four-digit area code (from hearing the old codes, "0171" and "0181" repeated previously); and that incorrectly formatted caller ID data continues to be transmitted on some telephone networks even as of 2012. Also, many users are unaware that there is any local dialling procedure, probably because of the increasing popularity of mobile phones (from which the full national number must always be dialled).

Numerous examples of incorrectly formatted telephone numbers may still be seen in and around London, including signwriting on shop-fronts and commercial vehicles, and in newspaper advertisements. The incorrectly placed pauses are also heard in speech everywhere: in radio and television advertisements, and said by office workers misquoting their office numbers as "0207 xxx xxxx" - unaware that this perpetuates the confusion.

While some clear publicity explaining the change was produced, BT's directory-assistance service quoted the codes incorrectly and, until November 2009, their online phonebook still incorrectly showed "0207" and "0208" as "London Inner" and "London Outer" codes respectively.

A 2005 television advertisement for the mobile telephony provider O2 promoted a service that allows a user to select two area codes they can call for a reduced price; it also incorrectly showed 0207 and 0208 as different "area codes".

Outside of London, in the areas that had newly-assigned 011x codes in the 1990s, many mistakenly believed that the added digit necessary to lengthen the subscriber number to seven digits was part of their new area code, largely because these places originally had traditional area codes (being non-Director areas), and as a result, many misquoted their numbers in the 011xx xxxxxx format, rather than in the correct 011x xxx xxxx format. In Reading, the confusion was furthered by the fact dual running of the original 01734 and new 0118 codes was possible during the migration period, so it was possible to continue dialling the number locally in the six digit format until 1998, when seven digit numbers became mandatory. Because of this, many mistook the added 9 as being part of the new area code, rather than the subscriber number. Following the migration, new numbers beginning with 3xx, 4xx, 91x and 90x began to be issued.

Confusion is also caused by exchange automated changed number announcements where the voice synthesiser assumes that ALL area codes have four digits and places the spoken pause incorrectly.

New London numbers

From June 2005 new local numbers in London have begun to be allocated with an initial "3" - for example, (020) 3222 1234. Owing to the lingering confusion, people unaware of the correct format are beginning to erroneously assume that there is now a new London code, "0203", and some people confuse this with the dialling code for Coventry (which used to be 0203 prior to PhONEday). Even some newspapers, both local and national, have given this misinformation. Some people report mis-dialling of London 3xxx xxxx numbers, where callers are dialling 0207 in front of the local number part instead of just 020. This call connects to the owner of an (020) 73xx xxxx number (in the process, ignoring the final digit actually dialled) instead of to the expected person.

The geographical significance of the "7" or "8" has been lost with regard to new number issues so that, for example, some newly allocated numbers in central London now begin with an "8".

Other numbers

Although the problem is most prevalent in London, similar misconceptions also affect other area codes which were created as a result of PhONEday and the Big Number Change.

Area	Old numbering	Misconception	Correct new numbering
Belfast	(01232) xxxxxx	02890 xxxxxx	(028) 90xx xxxx
Bristol	(0272) xxxxxx	01179 xxxxxx	(0117) xxx xxxx
Cardiff	(01222) xxxxxx	02920 xxxxxx	(029) 2xxx xxxx
Coventry	(01203) xxxxxx	02476 xxxxxx	(024) 7xxx xxxx
Leeds	(0532) xxxxxx	01132 xxxxxx	(0113) xxx xxxx
Leicester	(0533) xxxxxx	01162 xxxxxx	(0116) xxx xxxx
Nottingham	(0602) xxxxxx	01159 xxxxxx	(0115) xxx xxxx
Portsmouth	(01705) xxxxxx	02392 xxxxxx	(023) 9xxx xxxx
Reading	(01734) xxxxxx	01189 xxxxxx	(0118) xxx xxxx
Sheffield	(0742) xxxxxx	01142 xxxxxx	(0114) xxx xxxx
Southampton	(01703) xxxxxx	02380 xxxxxx	(023) 8xxx xxxx

International notation of UK numbers

The United Kingdom adopts an open dialling plan for area codes within its public switched telephone network. Therefore, all area codes have a preceding "0" when dialling from within the United Kingdom. When dialling a UK number from abroad, the zero is not included. Because of this, it has become common (but incorrect) practice to write the number with the 0 in parentheses, for example: +44 (0) 20 7946 0234. However, someone calling this number from the United States may mistake the trunk code for a single-digit area code, as NANP area codes are often written in parentheses, dial all the digits and result in a failed call. ITU-T Recommendation E.123 states that parentheses should not be used in the international notation, the correct format being +44 20 7946 0234.

See also

• List of dialling codes in the United Kingdom
• Telecommunications in the United Kingdom
• Telephone numbering plan