What is the country code for GB?

The country code for the United Kingdom of Great Britain and Northern Ireland is +44.

How are mobile numbers structured in GB?

Mobile numbers in the UK start with the prefix 07 and are 11 digits long, formatted as 07XXX XXXXXX. For example, a valid mobile number could be 07911 123456.

What are the dialing procedures for international calls to GB?

To call a UK number from abroad, dial the international access code (e.g., 00), followed by the UK country code (+44), and then the UK number without the leading 0. For example, to call the London number 020 7946 0958 from abroad, you would dial +44 20 7946 0958.

Is number portability supported in GB?

Yes, the UK supports number portability for both mobile and fixed-line numbers. This allows users to retain their phone numbers when switching between service providers.

What are the major telecom operators in GB and their typical number ranges?

The major telecom operators in the UK include EE, O2, Vodafone, and Three. Mobile numbers typically start with the prefix 07, which is common across all these operators.

What is the national prefix for UK numbers?

The national prefix for UK numbers is 0.

What is the country code for the United Kingdom?

The country code for the United Kingdom is +44.

How do I dial a UK number from abroad?

To dial a UK number from abroad, use the format: +44 followed by the UK number without the leading 0. For example, +44 20 7946 0958.

What are some examples of UK geographic area codes?

Examples of UK geographic area codes include 020 for London and 0161 for Manchester.

How do I dial a UK landline number domestically?

To dial a UK landline number domestically, dial the area code followed by the subscriber number, such as 020 7946 0958.

What is the standard length of a UK mobile number?

A UK mobile number is typically 11 digits long.

What prefixes do UK mobile numbers start with?

UK mobile numbers start with the prefix 07.

What are non-geographic numbers in the UK?

Non-geographic numbers in the UK are used for services not tied to a specific location and include prefixes like 03, 08, and 09.

What is the format for UK toll-free numbers?

UK toll-free numbers typically start with 0800 or 0808 and are formatted as 0800 XXX XXX.

How are UK premium-rate numbers formatted?

UK premium-rate numbers use the 09 prefix and are formatted as 09XX XXX XXXX.

What is number portability in the UK?

Number portability in the UK allows users to retain their phone numbers when switching providers, available for fixed-line since 2001 and mobile since 2003.

Who regulates the UK telephone numbering plan?

The UK telephone numbering plan is regulated by Ofcom.

What is the international dialing prefix for calling out of the UK?

The international dialing prefix for calling out of the UK is 00.

What are the major telecom operators in the UK?

Major telecom operators in the UK include EE, O2, Vodafone, and Three.

How can developers validate UK phone numbers?

Developers can validate UK phone numbers using regular expressions specific to each number type, such as geographic, mobile, and non-geographic numbers.

What is the ITU-T E.164 standard?

The ITU-T E.164 standard is an international numbering plan that ensures unique, globally formatted numbers.

What prefix do UK freephone numbers use?

UK freephone numbers use the prefixes 0800 and 0808.

How are UK special-rate numbers formatted?

UK special-rate numbers, such as those beginning with 084 and 087, are formatted as 08XX XXX XXXX.

What should be considered when scheduling calls to UK numbers?

When scheduling calls to UK numbers, consider time zone differences to ensure appropriate timing.

What is the purpose of non-geographic numbers in the UK?

Non-geographic numbers in the UK are used for services that are not location-specific, such as customer service lines and helplines.

United Kingdom Phone Number Guide

Quick Reference

Country: United Kingdom of Great Britain and Northern Ireland
Country Code: +44
International Prefix: 00
National Prefix: 0

Overview

This comprehensive guide explores the United Kingdom's telephone numbering plan, offering insights into number structures, dialing procedures, and regulatory frameworks. Essential for telecom professionals and developers, this guide ensures accurate handling of UK phone numbers.

Number Formats

General Number Structure

The UK's numbering plan, regulated by Ofcom, adheres to the ITU-T E.164 standard. Numbers vary by service type, such as geographic, mobile, or special services.

Country Code: +44
Trunk Code (National Prefix): 0
Area Code: Varies (e.g., 020 for London, 0161 for Manchester)
Subscriber Number: Varies by area code

Geographic Numbers

Geographic numbers are location-specific, typically starting with 01 or 02.

Format: 0XXX XXX XXXX (for most areas)
Example: 020 7946 0958 (London)

Mobile Numbers

UK mobile numbers start with 07 and are 11 digits long.

Format: 07XXX XXXXXX
Example: 07911 123456

Non-Geographic Numbers

Non-geographic numbers are used for services not tied to a location.

03 Numbers: Standard geographic rates
- Format: 03XX XXX XXXX
- Example: 0333 123 4567
08 Numbers: Freephone (0800, 0808) and special-rate services (084, 087)
- Format: 08XX XXX XXXX
- Example: 0800 123 4567 (Freephone)
09 Numbers: Premium-rate services
- Format: 09XX XXX XXXX
- Example: 0906 123 4567

Toll-Free Numbers

Toll-free numbers typically start with 0800 or 0808.

Format: 0800 XXX XXX or 0808 XXX XXX
Example: 0800 111 1111

Premium Rate Numbers

Premium services use the 09 prefix.

Format: 09XX XXX XXXX
Example: 0906 123 4567

Number Format Table

Type	Prefix	Example	Length
Geographic	01, 02	020 7946 0958	10 digits
Mobile	07	07911 123456	11 digits
Non-Geographic	03	0333 123 4567	10 digits
Freephone	0800, 0808	0800 111 1111	10 digits
Special Rate	084, 087	0845 123 4567	10 digits
Premium Rate	09	0906 123 4567	10 digits

Regular Expressions for Number Validation

To validate UK phone numbers, use these regular expressions:

Geographic Numbers: ^0[1-2]\d{9}$
Mobile Numbers: ^07\d{9}$
Non-Geographic Numbers: ^0(?:3|8|9)\d{8}$
Toll-Free Numbers: ^0800\d{6}$
Premium Rate Numbers: ^09\d{8}$

Dialing Procedures

Domestic Calls

Landline to Landline: Dial area code + subscriber number. Example: 020 7946 0958.
Landline to Mobile: Dial mobile number directly. Example: 07911 123456.
Mobile to Mobile: Dial mobile number directly. Example: 07911 123456.

International Calls

Outgoing: Dial 00 + country code + national number. Example: 00 1 202 555 0123 (USA).
Incoming: From abroad, dial +44 + UK number without leading 0. Example: +44 20 7946 0958.

Number Portability

The UK supports number portability, allowing retention of phone numbers when switching providers. Introduced for fixed-line in 2001 and mobile in 2003.

Major Telecom Operators

Major UK telecom operators include:

EE (Everything Everywhere)
O2
Vodafone
Three

These operators manage a wide range of mobile and fixed-line services. Mobile numbers typically start with 07.

Regulatory Authority

The UK's numbering plan is regulated by Ofcom. For updates, visit the Ofcom website.

ITU-T Recommendations

The UK follows the ITU-T E.164 standard, ensuring unique, globally formatted numbers.

Number Allocation and Management

Managed by Ofcom, numbers are allocated to operators who assign them to subscribers. Ofcom oversees special numbers like emergency and premium-rate services.

Technical Considerations

For Developers and Systems Administrators

Validation: Use regular expressions for UK number validation.
Normalization: Store numbers in international format (+44) to avoid ambiguity.
Portability: Implement systems supporting number portability, especially for mobile numbers.
Time Zones: Consider time zone differences for scheduling calls/messages to UK numbers.

For the latest updates on telecommunications regulations in the United Kingdom, refer to the official Ofcom website.