How UK Phone Numbers Are Structured
UK phone numbers follow a format regulated by Ofcom, the UK's communications regulator. Unlike the uniform 10-digit format used in the US, UK numbers vary in length depending on the type of service and the region. A typical UK number looks like this: 020 7946 0958 (London landline) or 07911 123456 (mobile).
All UK numbers, when dialled from abroad, begin with the country code +44, and the leading 0 of the area code is dropped.
The Structure of a UK Landline Number
A UK geographic number is made up of:
- STD code (Subscriber Trunk Dialling code): The area code, between 2 and 5 digits, always starting with 0.
- Local number: The remaining digits, making the full number (including area code) 11 digits in total.
Major UK City Area Codes
| City | Area Code | Example Number |
|---|---|---|
| London | 020 | 020 7XXX XXXX |
| Birmingham | 0121 | 0121 XXX XXXX |
| Manchester | 0161 | 0161 XXX XXXX |
| Leeds | 0113 | 0113 XXX XXXX |
| Glasgow | 0141 | 0141 XXX XXXX |
| Edinburgh | 0131 | 0131 XXX XXXX |
| Liverpool | 0151 | 0151 XXX XXXX |
| Bristol | 0117 | 0117 XXX XXXX |
| Sheffield | 0114 | 0114 XXX XXXX |
| Nottingham | 0115 | 0115 XXX XXXX |
UK Mobile Number Prefixes
Unlike landlines, UK mobile numbers all begin with 07 and are 11 digits long. Different mobile network operators are allocated specific ranges within the 07 block:
- 07400–07699: Various UK mobile operators
- 07700–07799: Mixed allocation (some are used for drama/fiction by Ofcom to avoid real numbers appearing in media)
- 07800–07999: Various operators including Vodafone, EE, O2, Three
The specific prefix alone does not reliably identify which operator holds the number today, due to number portability.
Non-Geographic Number Prefixes
UK numbers that don't represent a specific location include:
- 0800 / 0808: Freephone — free to call from mobile and landline.
- 0845 / 0870: Non-geographic — may carry call charges; often used by businesses.
- 0900 / 0906 / 0909: Premium rate — high per-minute charges apply.
- 03xx: National rate numbers — charged at the same rate as geographic numbers.
- 116xxx: Social purpose numbers (e.g., 116 123 is the Samaritans helpline).
How to Identify an Unknown UK Number
If you receive an unfamiliar UK number, look at the prefix to get a general idea:
- Numbers starting with 01 or 02 are geographic landlines — the area code tells you the region.
- Numbers starting with 07 are mobile phones.
- Numbers starting with 08 or 09 may carry special charges — look them up before calling back.
- Use Ofcom's numbering database or a trusted reverse lookup service to check specific numbers.
Calling the UK from Abroad
To call any UK number from overseas, use the format: +44 followed by the UK number without its leading 0. For example, the London number 020 7946 0958 becomes +44 20 7946 0958.