Locale Summary
| Locale name | United States |
|---|---|
| ISO code | US |
| Region | North America |
| Mobile country code | 310, 311, |
| Dialing code | +1 |
Guidelines
| Two-way SMS supported | Yes |
|---|---|
| Message length | 1600 characters. |
| Twilio MMS support | Supported |
| Sending SMS to landline numbers | Twilio 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’s customers, including their end users and clients, must comply with applicable laws, regulations, Twilio's policies, including, but not limited, to the Twilio Acceptable Use Policy and the Twilio Messaging Policy, and industry standards, including, but not limited to, telecommunications providers’ policies. U.S. telecommunications providers may assess fees for non-compliant A2P traffic, and Twilio will pass these fees onto you. To date, T-Mobile is the first U.S. telecommunications provider to announce non-compliance fees for violations of T-Mobile’s Code of Conduct. Twilio will update these guidelines accordingly if/when additional U.S. telecommunications providers announce non-compliance fees. T-Mobile non-compliance fees are as follows:
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Phone Numbers & Sender ID
| Alphanumeric | Long Code | Short Code | Toll Free | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pre-registration | Dynamic | Domestic | International | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Operator network capability | Not Supported | Not Supported | Supported | Not Supported | Supported | Supported | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Twilio supported | Not Supported | Not Supported | Supported | Not Supported | Supported | Supported | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Sender ID preserved | No | No | Yes | No | Yes | Yes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Provisioning time | --- | --- | Requires registration | --- | 6 - 10 weeks | Requires Verification | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| UCS-2 support | --- | --- | --- | --- | --- | --- | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Use case restrictions | --- | --- |
For additional insight into these uses cases, including limitations, and exceptions, visit: Forbidden message categories for SMS and MMS in the US and Canada | --- |
For additional insight into short code requirements see https://www.twilio.com/guidelines/us/short-code |
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 | Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. | Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. | Refer to our FAQ for long code best practices. Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. | Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. | Refer to our FAQ for short code best practices. Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. | Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Alphanumeric - Pre-registration | |
|---|---|
| Operator network capability | Not Supported |
| Twilio supported | Not Supported |
| Sender ID preserved | No |
| Provisioning time | --- |
| UCS-2 support | --- |
| Use case restrictions | --- |
| Best practices | Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. |
| Alphanumeric - Dynamic | |
|---|---|
| Operator network capability | Not Supported |
| Twilio supported | Not Supported |
| Sender ID preserved | No |
| Provisioning time | --- |
| UCS-2 support | --- |
| Use case restrictions | --- |
| Best practices | Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. |
| Long Code - Domestic | ||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operator network capability | Supported | |||||||||||||||||||||
| Twilio supported | Supported | |||||||||||||||||||||
| Sender ID preserved | Yes | |||||||||||||||||||||
| Provisioning time | Requires registration | |||||||||||||||||||||
| UCS-2 support | --- | |||||||||||||||||||||
| Use case restrictions |
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. Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. |
| Long Code - International | |
|---|---|
| Operator network capability | Not Supported |
| Twilio supported | Not Supported |
| Sender ID preserved | No |
| Provisioning time | --- |
| UCS-2 support | --- |
| Use case restrictions | --- |
| Best practices | Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. |
| Short Code | ||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operator network capability | Supported | |||||||||||||||||||||
| Twilio supported | Supported | |||||||||||||||||||||
| Sender ID preserved | Yes | |||||||||||||||||||||
| Provisioning time | 6 - 10 weeks | |||||||||||||||||||||
| UCS-2 support | --- | |||||||||||||||||||||
| Use case restrictions |
For additional insight into short code requirements see https://www.twilio.com/guidelines/us/short-code | |||||||||||||||||||||
| Best practices | Refer to our FAQ for short code best practices. Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. |
| Toll Free - Domestic | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operator network capability | Supported | |||||||||||||
| Twilio supported | Supported | |||||||||||||
| Sender ID preserved | Yes | |||||||||||||
| Provisioning time | Requires Verification | |||||||||||||
| UCS-2 support | --- | |||||||||||||
| Use case restrictions |
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 | Note: The euro symbol (€) is not supported; avoid using this character in message submission toward the United States. |
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.