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.



Use Cases

Short codes are ideal for high-throughput (100 messages per second by default) programmatic messaging. Short codes are approved for specific use cases, so if you are experiencing carrier filtering on long codes you may be a good candidate for short codes.

Some of the most common use-cases for short codes in the UK include: 

  • Two-factor authentication (2FA) or one-time passwords (OTP)
  • Promotional or marketing alerts
  • Account alert notifications
  • Reminders (appointments, upcoming payments, etc.)


Short codes can only message users on carriers within the countries in which they are provisioned. AlthoughTwilio can provision short codes in multiple countries, if your customers are not located in the UK, you should not obtain a UK short code.

Short codes require express consent from end users before any SMS can be sent; if you cannot obtain consent then you should not use a short code.

Twilio and/or the carriers will not support certain types of campaigns, including: 

  • Those in which express end-user consent cannot be obtained. This includes friend-to-friend invite-based campaigns, as well as opt-ins obtained through lead generation.
  • Those containing sexual/adult content (which is prohibited by Twilio’s AUP).

Note: Campaigns dealing with age-restricted content (alcohol, gambling, etc.) are allowed, but will be evaluated on a case-by-case basis by UK carriers.

The notice period before returning the Short Code is 1 month.

Other Options

Traditional long-code or toll-free SMS are the best alternatives.


A completed Twilio UK short-code application, submitted through your Twilio console. Because UK carriers do not require example messages when filing for a short code, our application does not ask for them.


12 - 16 weeks, once you submit all required information and documentation.

Please expect delays on any applications submitted from mid December through early January, as the wireless carriers have an annual provisioning freeze during this time.

Regulatory Bodies

Multiple entities determine what is or is not permitted on a given short code.

  1. Twilio will not approve short code applications that violate our AUP or Messaging Policy.
  2. Twilio’s providers perform their own compliance checks prior to sending applications to the carriers for review.These providers may have their own policies and rules about what they will or will not submit, although they generally align with the carriers. 
  3. Finally, each carrier may approve or reject any use case on their network, even if all requirements are met.


Click to see SMS pricing, including for short codes.

Next Steps

Once approved, you must configure your short code to respond to the mandatory compliance keywords HELP and STOP and implement proper blacklist functionality for STOP requests. You can either build this functionality yourself or leverage Twilio’s Advanced Opt Out feature.

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.