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. The telephone area code for most of Greater London and some surrounding areas is 020, not "0207", "0208" or "0203". A study was commissioned in 2005 which found that only 13 per cent of respondents correctly identified the 020 code for London without prompting: 59 per cent incorrectly identified it as "0207" or "0208". This is not just an issue of number appearance; the correct way to call a London landline number from a landline within the London telephone area is to dial the last 8 digits. The trunk prefix "0", and area dialling code "20", if included, are ignored. Other area codes with similarly widespread misconceptions about the correct area code 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 dialled within the same area, the trunk prefix and area code need not be dialled, but are ignored if they are. Owing 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 Aberdeen (01224), Bradford (01274), Brighton (01273), Middlesbrough (01642) and Milton Keynes (01908). Specifically, the requirement to dial the full number allowed for numbers to be allocated in which the first digit after the area code begins with a zero or a one. This