How to Use Toll-Free Phone Numbers for SMS and MMS
How to Use Toll-Free Phone Numbers for SMS and MMS
Section titled “How to Use Toll-Free Phone Numbers for SMS and MMS”Toll-free numbers are recognized as an A2P (Application-to-Person) messaging channel by major Canadian and US carriers — but only once the number is verified. Carriers block texts from unverified toll-free numbers.
Approved Use Cases
Section titled “Approved Use Cases”Toll-free messaging is well-suited for transactional and customer-facing use cases:
- One-time passwords (OTP) and verification codes
- Account-related alerts and notifications
- Customer care messaging, including automated responses and satisfaction surveys
- Promotional or marketing messages (with strict opt-in compliance — see best practices below)
Toll-Free Messaging Best Practices
Section titled “Toll-Free Messaging Best Practices”Carrier filtering on toll-free SMS targets spam, fraud, and policy violations. Compliant senders generally see low filtering rates. To maintain deliverability:
| Practice | Details |
|---|---|
| Obtain opt-in consent | Get clear consent before sending. Opt-in does not need to be via SMS. |
| Provide easy opt-out | Include “Reply STOP to unsubscribe” in your first message to each recipient. |
| Maintain low opt-out rates | High STOP rates signal unwanted traffic to carriers. |
| Use branded, shortened URLs | Avoid generic free URL shorteners (bit.ly, tinyurl). Use custom branded short links. |
| Do not snowshoe | Spreading the same content across multiple toll-free numbers is specifically targeted by carrier filtering systems. |
Toll-Free Verification
Section titled “Toll-Free Verification”Verification is required before a toll-free number can send SMS. It needs your business details (legal name, address, website, contact), your use case with sample messages, and proof of how people opt in to your texts. Review can take up to about 5 business days. Contests, sweepstakes, gambling, cryptocurrency, loan offers and debt relief, and cannabis, alcohol or tobacco promotions cannot be verified.
Self-serve toll-free verification is not available in Switchboard yet. Contact SIPSTACK Support to ask about it.
Toll-Free vs. Short Code
Section titled “Toll-Free vs. Short Code”| Factor | Toll-Free | Short Code |
|---|---|---|
| Voice calls | Yes | No |
| SMS throughput | 3 seg/sec (default, increasable) | 100 seg/sec (default, increasable) |
| Best for | Transactional, moderate-volume A2P | High-volume marketing and promotional |
| Setup time | Verification required (up to about 5 business days) | Weeks (application process required) |
Short code numbers remain the best option for high-volume marketing or promotional messaging in Canada and the US. Toll-free is a strong alternative for businesses that need combined voice and messaging capabilities, or are not ready to apply for a dedicated short code.