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UNITED KINGDOM (GB)

Country Summary

Country nameUnited Kingdom
ISO codeGB
RegionEurope
Mobile country code234, 235
Dialing code+44

Guidelines

Two-way SMS supported Yes
Number portability availableYes
Twilio concatenated message supportYes
Message lengthInbound: GSM 3.38=160, Unicode=70 Outbound: GSM 3.38=160, Unicode=70
Twilio MMS supportConverted to SMS with embedded URL
Sending SMS to landline numbersTwilio will not check whether the number is a landline and will attempt to send it to our carrier for delivery. Some carriers will convert the SMS into text-to-speech messages via voice calls.
Compliance considerations

SMS-to-voice functionality is in widespread use in the UK, and as a result, Twilio will not reject messages sent to landlines. Please be aware of this fact because it may not be the desired behavior for your application. If this is not the desired behavior, Twilio Support can help.

Twilio strongly encourages customers to review proposed use cases with qualified legal counsel to make sure that they comply with all applicable laws. The following are some general best practices:

  1. Get opt-in consent from each end user before sending any communication to them, particular for marketing or other non-essential communications.
  2. Only communicate during an end user's daytime hours unless it is urgent.
  3. SMS campaigns should support HELP/STOP messages, and similar messages, in the end user's local language.
  4. Do not contact end users on do-not-call or do-not-disturb registries.

Phone Numbers & Sender ID

Toll FreeLong CodeShort Code
DomesticInternationalDomesticInternational
Operator network capability --- --- SupportedSupportedSupported
Twilio supported --- ---
Learn more
SupportedSupportedSupported
Sender ID preserved --- --- YesYesYes
Provisioning time------N/AN/A8-12 weeks
UCS-2 support------SupportedSupportedSupported
Use case restrictions------

Virgin Mobile no longer support SMS to UK landline numbers

N/A

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 (cannabis, alcohol, gambling, etc.) are allowed, but will be evaluated on a case-by-case basis by UK carriers.

Best practices------

N/A

N/A

Refer to our FAQ for short code best practices: https://support.twilio.com/hc/en-us/articles/223134887-Requirements-for-UK-short-codes.

Toll Free - Domestic
Operator network capability ---
Twilio supported ---
Sender ID preserved ---
Provisioning time---
UCS-2 support---
Use case restrictions---
Best practices---
Toll Free - International
Operator network capability ---
Twilio supported ---
Learn more
Sender ID preserved ---
Provisioning time---
UCS-2 support---
Use case restrictions---
Best practices---
Long Code - Domestic
Operator network capabilitySupported
Twilio supportedSupported
Sender ID preservedYes
Provisioning timeN/A
UCS-2 supportSupported
Use case restrictions

Virgin Mobile no longer support SMS to UK landline numbers

Best practices

N/A

Long Code - International
Operator network capabilitySupported
Twilio supportedSupported
Sender ID preservedYes
Provisioning timeN/A
UCS-2 supportSupported
Use case restrictions

N/A

Best practices

N/A

Short Code
Operator network capabilitySupported
Twilio supportedSupported
Sender ID preservedYes
Provisioning time8-12 weeks
UCS-2 supportSupported
Use case restrictions

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 (cannabis, alcohol, gambling, etc.) are allowed, but will be evaluated on a case-by-case basis by UK carriers.

Best practices

Refer to our FAQ for short code best practices: https://support.twilio.com/hc/en-us/articles/223134887-Requirements-for-UK-short-codes.

Alphanumeric - Pre-registration
Operator network capabilityNot Required
Twilio supported ---
Sender ID preserved ---
Provisioning timeN/A
UCS-2 supportN/A
Use case restrictions

N/A

Best practices

N/A

Alphanumeric - Dynamic
Operator network capabilitySupported
Twilio supported Supported
Learn more
Sender ID preservedYes
Provisioning timeN/A
UCS-2 supportSupported
Use case restrictions

N/A

Best practices

N/A

Phone Numbers & Sender ID (continued)

Alphanumeric
Pre-registrationDynamic
Operator network capabilityNot RequiredSupported
Twilio supported --- Supported
Learn more
Sender ID preserved --- Yes
Provisioning timeN/AN/A
UCS-2 supportN/ASupported
Use case restrictions

N/A

N/A

Best practices

N/A

N/A

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.