United States (US)

Locale Summary

Locale name

United States

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



North America

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 include: 

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

In addition, US short codes are the only way to send messages that are truly free to your end users through Free-to-End-User messaging (additional fees and requirements apply).


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

Short codes require express consent from end users before an SMS can be sent; if you cannot obtain consent, 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 (prohibited by Twilio’s AUP).
  • Those whose sole purpose is to provide lead generation or data collection services. Typically, such campaigns are aggregation websites or services that do not offer actual products or services; instead, they simply connect users to companies that do offer them. Common examples include:
    • Loan companies that are not direct lenders
    • Job boards that do not have direct relationships with the companies whose job postings they display
  • Those that send messages on behalf of multiple financial institutions. 
  • Those in which more than a single entity controls message content and frequency. All short-code messaging must be controlled and vetted by a single entity, even if the messages are sent on behalf of multiple brands.
  • Those of companies whose privacy policies mention sharing or selling end-user personal information for any purposes other than fulfilling services. 
  • Gambling related content
  • Debt collections use cases

The following use cases are allowed. However, since the carriers impose additional requirements and scrutiny, they may take longer than usual to provision.

  • Age-restricted content (tobacco, alcohol, etc.)
  • Sweepstakes or contests
  • Loan-related use cases for direct lenders

Other Options

Toll-free numbers and 10DLC A2P are the best alternatives.


  1. A completed and submitted short-code application. Although every piece of information on our application is important, the following pieces are the most critical and must be fully completed to move forward..
    • Example messages must be specific and representative of actual messages that will be sent using the short code.
    • The SMS program brand’s website must be live before carriers will review the short code application..
  2. A compliant mockup of the end-user consent flow. This is a visual mockup of the end-user call to action, showing how users sign up to receive messages from your short code. There are specific requirements for what must be shown to users before they can consent to receive messages from a short code. Carriers will not approve consent flows that do not display these elements.
  3. A compliant screenshot, link, or mockup of the SMS Terms of Service. These terms do not need to be live on your website at the time of the application, but a draft is required before carriers will approve the short code program. The SMS Terms URL  must be live before the short code program is launched.
  4. A Letter of Authorization from the brand appearing in your messaging.


The Short Code process is separated into two primary steps, each with their own timelines.

  1. Twilio Internal Review: Once you have submitted your application a Twilio Short Code specialist will reach out and work with you to review all submitted materials for compliance. Individual customer review times will vary greatly, but most customers can expect to move forward in a few weeks.
  2. Carrier Review: After your application has passed Twilio's Internal Review and been paid for it will be sent to carriers. The time from payment to approval with the major carriers is about 6-10 weeks. Please note that approvals are subject to carrier discretion, and approval may take longer depending on use case and industry.

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.
  2. Customers must adhere to the Telephone Consumer Protection Act (TCPA) requirements.
  3. 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.
  4. The CTIA is a carrier trade association that has specific requirements for short-code campaigns; these requirements are detailed in the CTIA Short Code Compliance Handbook.
  5. 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.

In addition, you should regularly process your carrier’s reassigned and deactivated phone number lists to ensure messages aren’t sent to users who have not opted in to receive them.

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.