A Guide to Sending International SMS with US Toll-Free Numbers and AWS End User Messaging

AWS End User Messaging now supports international SMS capabilities for US Toll-Free Numbers (TFNs). This new feature allows businesses to use a single US TFN to send SMS messages to over 150 countries, simplifying global outreach. It primarily benefits customers who need to send one-way transactional alerts—like one-time passwords (OTPs) or shipping notifications—and businesses that want to rapidly prototype and test their messaging strategy in new international markets without the overhead of procuring country-specific numbers.

This guide will walk you through the pros and cons of this feature and show you how to enable it and when to use it versus traditional, country-specific sending methods.

What Are International US Toll-Free Numbers?

An International US Toll-Free Number is a standard US TFN that has been enabled with the capability to send SMS messages to destinations outside of the United States. This feature is backward compatible, meaning you can enable it on any new or existing US TFNs in your account.

How to Enable International Sending

There are three primary ways to enable this feature for your US Toll-Free Numbers:

Enable international sending when registering a new number in the console.
Enable international sending for an existing number in the console.
Enable international sending for an existing number via the AWS CLI.

1. Enable When Registering a New US Toll-Free Number (Console)

From the AWS End User Messaging console, navigate to Manage SMS
From the AWS End User Messaging console, navigate to Configurations > Phone numbers > and select Request originator
Step 1: Select country, select the United States (US) as your destination country
Under Step 2: Define use case, configure the various options listed for your intended Messaging use case, and select Yes to enable International sending, prior to clicking Next
For Step 3: Select originator type, select Toll-free, validate your Resource policy choices, select Next
In Step 4: Review and request: Verify the information you entered is correct and select Request. Please note: US Toll-Free Number registration requests can take approximately 15 business days to be approved.

For more information, see Request a phone number in AWS End User Messaging SMS

2. Enable for an Existing US Toll-Free Number (Console or CLI)

If you have already acquired a TFN, you can enable the international sending feature at any time.

Using the AWS Management Console:

Navigate to Configurations > Phone numbers > and select an existing Toll-free number
Locate the International sending tab and choose Edit settings
Check the Enable international sending capability box in your phone number details
- Save Changes

Using the AWS CLI

The update-phone-number command allows you to modify a phone number’s capabilities, while the describe-phone-numbers command allows you to verify its status.

1. To Enable International Sending:

Use the --international-sending-enabled flag

aws pinpoint-sms-voice-v2 update-phone-number \
    --phone-number-id "phone-a1b2c3d4e5f67890" \
    --international-sending-enabled \
    --region us-east-1

Note: Replace "phone-a1b2c3d4e5f67890" with your actual phone number’s ID

2. To Disable International Sending:

Use the --no-international-sending-enabled flag

aws pinpoint-sms-voice-v2 update-phone-number \
    --phone-number-id "phone-a1b2c3d4e5f67890" \
    --no-international-sending-enabled \
    --region us-east-1

Expected Response (for update-phone-number):

A successful command returns the full JSON object for the phone number. Confirm the change by checking that the InternationalSendingEnabled value is true

{
    "PhoneNumberArn": "arn:aws:sms-voice:us-east-1:111122223333:phone-number/phone-a1b2c3d4e5f67890",
    "PhoneNumberId": "phone-a1b2c3d4e5f67890",
    "PhoneNumber": "+18005550199",
    "Status": "ACTIVE",
    "IsoCountryCode": "US",
    "MessageType": "TRANSACTIONAL",
    "NumberCapabilities": [
        "SMS"
    ],
    "NumberType": "TOLL_FREE",
    "MonthlyLeasingPrice": "2.00",
    "TwoWayEnabled": true,
    "InternationalSendingEnabled": true,
    "CreatedTimestamp": "2025-08-15T10:30:00.123Z"
}

3. To Verify the Current Status:

Use the describe-phone-numbers command with your Phone Number ID to check its current configuration at any time.

aws pinpoint-sms-voice-v2 describe-phone-numbers \
    --phone-number-ids "phone-a1b2c3d4e5f67890" \
    --region us-east-1

Benefits and Limitations

This feature offers a powerful new way to reach a global audience, but it’s important to understand where it shines and what its limitations are.

Benefits (Advantages)

Global Reach with a Single Number: Send SMS to over 150 countries using a single, existing US TFN.
Simplified Management: Avoid the operational overhead and cost of purchasing and managing a fleet of country-specific phone numbers.
Rapid Prototyping and Testing: Quickly test messaging campaigns in new international markets before committing to the best practice approach of acquiring dedicated in-country numbers.
Cost Optimization for One-Way Alerts: Provides a cost-effective method for sending high-volume, one-way transactional messages like OTPs, appointment reminders, and shipping notifications globally.
Speed to Implement: Toll-Free number registration is currently the fastest way to get an originator in the US and begin sending SMS. Check here for current timelines.

Limitations & Technical Considerations

Two-Way SMS is Limited to the US and Canada: Reliable, two-way SMS conversations are only supported for recipients in the United States and Canada.
One-Way Only for All Other Countries: For all other destinations, this is a one-way only.
Best-Effort Deliverability: Sending outside of the US and Canada is on a “best-effort” basis. The phone number that appears on the recipient’s device may be replaced with a local number or Sender ID, which is why two-way messaging will not work for these destinations. For more details on maximizing delivery, please read A Guide to Optimizing SMS Delivery and Best Practices.
Managed Opt-Out is Not Guaranteed Internationally: The automatic STOP reply functionality does not work for destinations outside of the US and Canada. For international recipients, you must provide an alternative opt-out method.
Standard Throughput (3 MPS): International TFNs have a default throughput of 3 Message Parts Per Second (MPS). For high-volume, high-throughput campaigns, dedicated country-specific numbers (like short codes) are the recommended best practice.

Understanding the Cost

The pricing for this feature is straightforward:

No Additional Monthly Fees: There is no extra charge to enable the international sending capability on your US TFN. You only pay the standard monthly lease for the number itself.
Pay-Per-Use Messaging: You are billed for each outbound SMS message at the standard, per-message rate for the destination country.

For a complete and up-to-date list of prices by country, please visit the AWS End User Messaging Pricing page.

When to Use This vs. Country-Specific Numbers

Choosing the right tool depends on your use case. Here’s a simple comparison:

Considerations and Next Steps

Once you have enabled your international sending over US Toll-Free Numbers, you can enhance your messaging strategy by considering resilience, monitoring, and scalability. The following resources provide best practices for enhancing your sending.

Monitoring Delivery: To monitor delivery rates and patterns by country, you can use Configuration Sets to create event destinations. This allows you to stream SMS events (like DELIVERED or FAILED) to services like Amazon CloudWatch or Amazon Data Firehose for analysis.
Building Resilience: For implementing robust delivery, including automatic retry strategies for failed messages, we recommend reading our guide: How to build resilient SMS delivery with AWS End User Messaging.
Broader Global Strategy: For a deeper look at the strategic elements of a global SMS program, our post on How to Manage Global Sending of SMS with AWS End User Messaging provides valuable insights and includes a template for organizing use cases and selecting originators.

Conclusion

International SMS for US Toll-Free Numbers is a powerful strategic tool for businesses looking to simplify their global messaging. It excels at enabling rapid testing in new markets and efficiently delivering one-way transactional alerts across the globe from a single number.

However, it is not a replacement for the best practice of using dedicated, in-country phone numbers when reliable two-way conversations and guaranteed branding are critical to your campaign’s success. By understanding its benefits and limitations, you can strategically use this feature to get going quickly while planning a long-term move towards country-specific codes for your most important markets.

AWS Messaging Blog