UNITED STATES (US)

Country Summary

Country nameUnited States
ISO codeUS
RegionNorth America
Mobile country code310, 311,
Dialing code+1

Guidelines

Two-way SMS supported Yes
Message length1600 characters. Sprint does not support concatenation and messages will be delivered as multiple segments.
Twilio MMS supportSupported
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

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.

Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States.

Phone Numbers & Sender ID

AlphanumericLong CodeShort Code
Pre-registrationDynamicDomesticInternational
Operator network capabilityNot SupportedNot SupportedSupportedNot SupportedSupported
Twilio supported Not Supported Not Supported SupportedNot SupportedSupported
Sender ID preservedNoNoYesNoYes
Provisioning time------Requires registration---6 - 10 weeks
UCS-2 support---------------
Use case restrictions------

High-risk financial services

Lead Generation Services

Debt collection or forgiveness

“Get rich quick” schemes

Illegal substances

Gambling

"S.H.A.F.T." use cases

For additional insight into these uses cases, including limitations, and exceptions, visit:  Forbidden message categories for SMS and MMS in the US and Canada

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High-risk financial services

Lead Generation Services

Debt collection or forgiveness

“Get rich quick” schemes

Illegal substances

Gambling

"S.H.A.F.T." use cases

For additional insight into these uses cases, including limitations, and exceptions, visit:  Forbidden message categories for SMS and MMS in the US and Canada

Best practices------

Refer to our FAQ for long code best practices.

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Refer to our FAQ for short code best practices.

Alphanumeric - Pre-registration
Operator network capabilityNot Supported
Twilio supported Not Supported
Sender ID preservedNo
Provisioning time---
UCS-2 support---
Use case restrictions---
Best practices---
Alphanumeric - Dynamic
Operator network capabilityNot Supported
Twilio supported Not Supported
Sender ID preservedNo
Provisioning time---
UCS-2 support---
Use case restrictions---
Best practices---
Long Code - Domestic
Operator network capabilitySupported
Twilio supportedSupported
Sender ID preservedYes
Provisioning timeRequires registration
UCS-2 support---
Use case restrictions

High-risk financial services

Lead Generation Services

Debt collection or forgiveness

“Get rich quick” schemes

Illegal substances

Gambling

"S.H.A.F.T." use cases

For additional insight into these uses cases, including limitations, and exceptions, visit:  Forbidden message categories for SMS and MMS in the US and Canada

Best practices

Refer to our FAQ for long code best practices.

Long Code - International
Operator network capabilityNot Supported
Twilio supportedNot Supported
Sender ID preservedNo
Provisioning time---
UCS-2 support---
Use case restrictions---
Best practices---
Short Code
Operator network capabilitySupported
Twilio supportedSupported
Sender ID preservedYes
Provisioning time6 - 10 weeks
UCS-2 support---
Use case restrictions

High-risk financial services

Lead Generation Services

Debt collection or forgiveness

“Get rich quick” schemes

Illegal substances

Gambling

"S.H.A.F.T." use cases

For additional insight into these uses cases, including limitations, and exceptions, visit:  Forbidden message categories for SMS and MMS in the US and Canada

Best practices

Refer to our FAQ for short code best practices.

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.