Telephone Numbers in the United Kingdom

Prefixes

Telephone numbers in the United Kingdom are regulated by the Office of Communications (Ofcom). The country is divided into various geographical areas, each with its own unique telephone prefix.

### Geographical Numbers

Numbers starting with 01 or 02 are considered normal phone numbers for residential and business lines. These numbers are typically divided into two parts:

* **Area Code**: The first part, which corresponds to a specific region in the country. For example:
+ 020 is associated with London
+ 0121 is associated with Birmingham
* **Telephone Number**: The second part, which is unique to each phone line.

### International Dialing

When calling from abroad, the international dialing format is as follows:

* **International Code**: +44 (country code)
* **Local Code** (without leading zero): The area code without the initial 0
* **Telephone Number**

### Selection within the Country

Within the UK, numbers can be dialed using either the full number or just the area code followed by the telephone number.

History of British Telephone Numbers

The introduction of local codes in the United Kingdom dates back to December 1958, with the completion of Subscriber Trunk Dialling (STD) codes in 1979. These early local area codes consisted of one zero and three digits.

### List of Area Codes

Below is a list of UK telephone prefixes, including current and no longer in use:

* **2-digit geographical prefixes**: Type 02x
* **3-digit geographical prefixes**:
+ Type 011x
+ Type 01x1
* **Geographical prefixes at 4 and 5 digits**:
+ Type 01xxx
+ Type 01xxxx
* **Geographical prefixes of type 012xx**
* **Geographical prefixes of type 013xx and 013xxx**
* **Geographical prefixes of type 014xx**
* **Geographical prefixes of type 015xx and 015xxx**
* **Geographical prefixes of type 016xx and 016xxx**

Note: This list is not exhaustive, but rather a selection from the provided sources.