Adaptive AI Knowledge Base
Phone, SMS & Calling
This article outlines essential best practices to help you improve SMS deliverability and avoid carrier restrictions. By following these guidelines, you can ensure your messages reach your audience reliably and stay compliant with carrier policies.
We are focused on helping our customers deliver trusted communications, and on making sure that the carrier does not block or suspend the account permanently based on bad usage.
As soon as the account hits the temporary suspension, all upcoming outbound SMS will fail until 00:00 AM UTC.
- 1Stop all your workflows, campaigns, triggers, and/or bulk actions to contacts who have not explicitly opted in to receive messages from the sub-account.
- 2Enable and customize the Opt-Out language and Sender ID message as per your use case so that all upcoming messages are not flagged.
- 3Discuss this with your client to ensure that no bulk communication, message blasts, or cold prospecting campaigns are sent in the near future before we receive your reply to the ticket.
How do I get the sub-account suspension removed early?
The sub-account suspension will be lifted in 24 hours. However, if the sub-account is permanently suspended, please refer to the article Why is your account suspended to unsuspend the sub-account.
How to prevent future SMS suspension
Include opt-out language ( reply STOP / CANCEL to unsubscribe ) in the first SMS sent to every new contact.
Include an introduction of yourself or your company in the first SMS sent to every new contact.
Avoid sending to landlines. Enable Number Intelligence — this feature looks up the number before sending and applies a temporary DND on the contact if it is not SMS-capable.
Using public URL shorteners like bit.ly or tinyurl.com can harm SMS deliverability. Carriers — especially
T-Mobile and AT&T — flag these as high risk due to their association with spam and phishing.
T-Mobile prohibits URL cycling and multiple redirects. Messages using such tactics may be blocked.
AT&T outright blocks public shorteners.
- Use or short URLs linked to your business domain.
- Limit redirects to, and avoid cloaking link destinations.
- When possible, include the to boost transparency (even if it takes extra characters).
Improving your URL practices can prevent filtering and ensure your messages reach their audience.
The messaging world is moving toward a state where, without these registrations, no messages will be delivered. You can view the Trust Center tab once the sub-account country is set to US.
Campaign verification can take up to 1 week. If it is not approved after a week, please raise a support ticket so we can escalate the request to TCR.
For future web form opt-in setups, include a checkbox so the lead gives consent when filling out the form (if that's where your leads opt in).
Below are examples of the web form opt-in flow.
When the Phone Number field is Mandatory in the web form opt-in:
- Consent checkboxes should be separated for both Marketing and Non-Marketing messages.
- Consent and.
- and at the footer.
When the Phone Number field is not Mandatory in the web form opt-in:
- A consent checkbox is not required when the Phone Number field is not mandatory.
- and at the footer.
The first message should state the source of how your leads opted in.
Add opt-in language so contacts are actively double opted-in via SMS and the web form checkbox (e.g., reply 1 to subscribe ).
Also, review our Messaging Policy for further guidance.