United Kingdom (GB)

Locale Summary

Locale name

United Kingdom

ISO code
The International Organization for Standardization two character representation for the given locale.




Dialing code
The dialing prefix used to establish a call or send an SMS from one locale to the given locale.



Portable Numbers

  • Geographic (local) numbers (+441,+442)
  • Mobile numbers (+447)
  • Non-geographic (national) numbers (+443)
  • Non-geographic (toll-free) numbers (+44808, +44800)


  • Most of International Phone Numbers have VOICE capability only. Only Mobile numbers have VOICE and SMS.
  • Most numbers are portable. In rare cases, some numbers are not, either because of how some service providers assign phone numbers, or because some providers do not have porting agreements with the major network operators.

Required Information

For Geo and Non-Geo numbers:

For Mobile numbers:


Once you submit all required documentation/information:

  • For Geographic (local) and Non-geographic up to 4 - 6 weeks, depending on the complexity of the port and time required by the current service provider.
  • For Mobile numbers up to 5-7 business days.

Regulatory Bodies

The Office of Communications (OFCOM)

Other Details

The most common reasons for a rejected port include:

  • Incorrect postcode.
  • Single- vs. multi-line geographic numbers. Associated numbers must be ported together as a range. To determine whether your number is a single- or multi-line number, reach out to your current service provider. 
  • Incorrect current provider and/or range holder information. Check with your current provider and the range holder of your phone number(s). 

Click to check the range holder. However, information about the current provider can only be confirmed by that provider.

Once you have this information, add the current provider on the LOA in the Current Operator field. You can leave the New Operator field blank.

How To Submit

Please submit your request via the porting form here.

You can find all the requirements needed here.

For the benefit of all our customers, these guidelines are provided to help you comply with applicable requirements and to help ensure Twilio's platform remains compliant with global telecommunications ecosystem requirements. These guidelines represent our current understanding of common compliance requirements generally applicable to Twilio and its customers, and do not constitute legal advice. By posting these guidelines, Twilio makes no assurances regarding the legal compliance of your application built using our APIs. You are expected to understand and abide by all compliance obligations applicable to your specific application. You should check these pages regularly for updates as telecommunications ecosystem requirements continue to evolve and change, and the information below may be updated or changed without notice.