Phone Number Formatting

How to write UK telephone numbers

General | Special numbers | Overseas | Programmers | Signage

Writing phone numbers correctly makes them easier to read and helps callers dial the right number. [How?]

Rules for landline numbers

  1. Separate the area code from the local number with a space
  2. Split longer local numbers with a space for readability
  3. Optionally, put the area code inside brackets

The length of area codes and local numbers varies across the UK, which means there are several valid formats:

FormatUsed forExamples
02x xxxx xxxxCardiff, Coventry, London, Portsmouth, Southampton and all of Northern IrelandCardiff
London
01x1 xxx xxxx
011x xxx xxxx
Other major citiesBirmingham
Leeds
01xxx xxxxxx
01xxx xxxxx
Smaller cities, provincial towns and rural areasGuildford
Stirling
01xxxx xxxxx
01xxxx xxxx
Rural north west England and BordersKeswick
Langholm

For specific information on individual areas, see the area code listings or the quick quide to writing numbers in major UK cities.

Special numbers

Mobile and non-geographic numbers don't have optional area codes so can largely be written in whichever pattern aids memorability.

The format 07xxx xxxxxx is recommended for mobile phones as it is used by the main mobile networks.

'08' numbers are best displayed in the style 08xx xxx xxxx to aid recognition of the various different services. For example, as the meaning of '0800' is widely understood, 0800 123 4567 is more likely to be recognised as a freephone number than 08001 234567.

From overseas

If you want people to call you internationally, remove the leading zero of your phone number and prefix it with '+44'. For example, London number (020) 7946 0018 becomes +44 20 7946 0018.

Never write '0044' instead of +44. Many countries do not use '00' for international dialling - such as the USA from which a caller would need to dial 01144 to reach the UK. Using the symbol '+' avoids this problem as it tells the caller to dial their country's international access code (whether 00, 011 or anything else) - and is also recognised by many mobile phones.

The complete pattern for programmers

Need to build number formatting into a piece of software or a database? The basic list of patterns and accompanying notes below show the various valid formats in the UK in 2014:

01### #####
01### ######
011# ### ####
01#1 ### ####
013873 #####
015242 #####
015394 #####
015395 #####
015396 #####
016973 #####
016974 #####
016977 ####
016977 #####
017683 #####
017684 #####
017687 #####
019467 #####
02# #### ####
03## ### ####
05### ######
0500 ######
07### ######
0800 ######
08## ### ####
09## ### ####


Notes to above:

  • # represents any digit between 0 and 9
  • There are also, exceptionally, two eight digit numbers in use which are not specifically included above: 0800 1111 and 0845 4647.
  • There are, as yet, no numbers beginning 04 or 06.

The list needs to be parsed in the order shown to work properly; the last match in the list is the one to use for any given number.

As an example, 01234567890 matches the second line of the list and no others, so is formatted as 01234 567890. Meanwhile the last line matched by the number 01134960018 is the third line in the list, so the correct formatting is 0113 496 0018.

Signage

On signage, it is helpful to display numbers in full, on a single line and with spaces in the correct place, to aid memorability and readability.

Here are examples for a small town that has the area code 01632 and six-digit local numbers.

Ways of displaying a phone number on a sign.
  1. The full number is displayed on one line, allowing it to be easily read and dialled.
  2. Placing brackets around the code can help distinguish the code (01632) from the local number. This could aid memorability by emphasising that in most cases only the last six digits need to be remembered and dialled.
  3. Brackets can look untidy, so different sizes and weights of lettering can have the same effect while looking more stylish.
  4. Giving the exchange name instead of the code could subtly add to the feeling of local identity or tradition. However, in most cases it is unhelpful and should be avoided - a visitor using their mobile phone may not know what code they need to insert before the local number, for example.
  5. Where space is very limited, the area code could be left out. Again, though, it is better to write out the full number where possible.

Browse the area code listings for specific guidance on how to write phone numbers in each area.

Telephones