UK Phone Number Format: How to Write and Dial UK Numbers (+44)

A UK mobile number has 11 digits and is written 07xxx xxxxxx, for example 07700 900123. Landline numbers are the same length, but the space goes after the area code: 020 7946 0018 in London, 0131 496 0454 in Edinburgh, 01632 960123 in most other places. From abroad, the UK phone code is +44: drop the first 0 and write +44 7700 900123. For apps, online forms and WhatsApp, use the same number with no spaces: +447700900123.

That covers most of what you need. The rest of this guide explains how to space every kind of UK number, why “+44 (0)” causes trouble, the mistakes that stop calls connecting, and which format to use where. Every sample number on this page comes from ranges Ofcom keeps for fiction and demonstrations, so none of them belongs to a real person.

UK phone number format at a glance

The space in a UK number separates the code from the rest of the number. Where it goes depends on how long the code is:

Type of number	Starts with	How to space it	Example
Mobile	07	07xxx xxxxxx	07700 900123
London, Southampton, Portsmouth, Coventry, Cardiff, Northern Ireland	020, 023, 024, 029, 028	02x xxxx xxxx	020 7946 0018
Large cities with a three-digit code, such as Leeds 0113, Birmingham 0121, Manchester 0161	011x or 01×1	01xx xxx xxxx	0131 496 0454
Most other towns and areas	01	01xxx xxxxxx	01632 960123
Non-geographic, such as 03 standard rate, 08 and 09 numbers	03, 08, 09	0xxx xxx xxxx	0306 999 0123

There is no law on spacing, and you will see small variations. The GOV.UK style guide, for instance, writes mobiles in three groups, as 07700 900 265. Either way is fine as long as the area code stays together. Splitting it, as in 0207 946 0018, gives readers the wrong idea about the code, which leads to the first common mistake below.

How many digits is a UK phone number?

Almost every UK number has 11 digits when written with the leading 0, and 10 digits after +44. That includes all mobiles. If you count 10 digits in a mobile number starting 07, a digit is missing.

There are a few old exceptions. A few dozen rural area codes still have some five-digit local numbers, and Brampton in Cumbria is the last place with four-digit ones. A handful of freephone numbers are short too: Childline’s 0800 1111 has only 8 digits. You will not meet a short mobile number, though.

The UK phone code: +44

+44 is the UK’s country code. To call a UK number from another country, you dial the code and then the number without its first 0:

1. Start with + on a mobile, or your country’s exit code on a landline, such as 00 in most of Europe or 011 from the US and Canada.
2. Add 44.
3. Add the UK number without the 0: 07700 900123 becomes 7700 900123.

So from France you would dial +44 7700 900123, or 00 44 7700 900123 from a landline. The + is the safer choice when you write a number down. The Office for National Statistics tells its writers not to use 00 in its place, because 00 does not work from every country. Calling the other way, from the UK to another country, you dial 00 or + followed by that country’s code.

Should you write +44 (0)?

You will often see numbers written as +44 (0)20 7946 0018. The bracketed 0 is meant to say “dial this in the UK, skip it from abroad”. Official guidance is split on it:

• GOV.UK uses it in its style guide, writing +44 (0)29 2018 0542.
• The Office for National Statistics tells its writers not to. It says brackets can affect how some assistive technology reads a number, and it follows the International Telecommunication Union standard instead: +44 3456 013034.

For practical purposes, leave the bracket out. Someone who dials exactly what they see, or a phone that reads the number off a web page, may keep the 0 and fail to connect. If your audience is only in the UK, write 020 7946 0018. If anyone abroad might call, write +44 20 7946 0018.

Saving numbers for WhatsApp, apps and online forms

Apps and websites store numbers in the international standard known as E.164: a +, the country code, then the number with no spaces, no brackets and no leading 0. A UK mobile in that form is +447700900123. The standard caps numbers at 15 digits in total, country code included.

• WhatsApp: save international contacts with +, the country code and the full number, dropping the leading 0. So 07700 900123 is saved as +447700900123.
• Online forms: if a form rejects your number, try it without spaces, then in +44 international format. Forms that ask you to pick the country first usually want the number without its 0.
• Your phone’s contacts: saving UK numbers as +44 means they still work when you travel, because your phone does not need to know which country you are in.

Common mistakes with UK numbers

• Writing 0207 or 0208 for London. London’s area code is 020. The 7 or 8 is the start of the local number, so the correct form is 020 7946 0018. The same applies to Cardiff, which is 029, not 02920.
• Keeping the 0 after +44. +44 07700 900123 has one digit too many and can fail to connect.
• Losing a digit. A UK mobile written with 10 digits is incomplete. Check it before you save it.
• Assuming every 07 number is a mobile. Numbers starting 070 are personal numbers and 076 are pagers, and both can cost much more to call. Our guide to UK mobile number prefixes explains which 07 ranges are real mobiles.
• Making up an example number. A random 07 number in an advert, app demo or document may belong to someone, who then gets the calls. Ofcom reserves 07700 900000 to 07700 900999 and 020 7946 0000 to 020 7946 0999, among others, for exactly this use.

Frequently asked questions

What is the UK mobile number format for international use?

+44 7xxx xxxxxx, such as +44 7700 900123. In apps and forms, remove the spaces: +447700900123.

Is +44 the same as 0044?

Both reach the UK from countries whose exit code is 00, which includes most of Europe. The + works from any mobile anywhere, so it is the better way to write a number down.

Do Jersey, Guernsey and the Isle of Man use +44?

Yes. They share the UK’s +44 dialling code and the same formats, such as 01624 for the Isle of Man and 07624 for its mobiles. Calls to them are not always charged like UK calls, though, which our prefix guide covers.

The short version

The UK phone number format comes down to this: write numbers in full, with the space after the area code: 07700 900123 or 020 7946 0018. For people abroad, swap the first 0 for +44. For apps and forms, use +44 with no spaces. Leave out “(0)”, and London is 020, not 0207.

Sources

• Ofcom — Telephone numbers for use in TV and radio drama, the reserved example ranges.
• GOV.UK — A to Z style guide, entry on telephone numbers.
• Office for National Statistics — Writing numbers, on +44 and the bracketed zero.
• WhatsApp — How to add an international phone number
• ITU — Recommendation E.164, the international numbering plan.
• Wikipedia — Telephone numbers in the United Kingdom, cross-checked for area code formats and number lengths.

Last reviewed 12 November 2026.