Help Center

Overview

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.

Error and Opt-out Rate Monitoring

We monitor the delivery rate of your overall account and take proactive measures to maintain healthy performance. If error or opt-out rates exceed certain thresholds, violation warning emails are sent, and temporary messaging restrictions may be automatically applied.

Note: Once an account hits temporary suspension, all outbound SMS will fail until 00:00 AM UTC.

Responding to Violation Emails

If you receive a violation email, immediately stop all workflows, campaigns, triggers, or bulk actions to contacts who have not explicitly opted in. Enable and customize opt-out language and sender ID messages to prevent future flags. Discuss with your client to ensure no bulk or cold prospecting campaigns are sent until you reply to the support ticket.

Understanding Error and Opt-out Rates

Opt-out Rate: A high opt-out rate indicates recipients are objecting, complaining, or marking messages as spam. A good rate is typically 0–1%.

Delivery Error Rate: A high error rate suggests sending to invalid numbers, unreachable devices, or landlines. It may also indicate carrier filters blocking due to past behavior. A good rate is typically 0–6%.

Removing Sub-account Suspension Early

Sub-account suspensions usually lift automatically after 24 hours. For permanent suspensions, refer to the account suspension article for resolution steps.

Preventing Future SMS Suspension

Follow these practices to reduce error rates and avoid flags:

Step 1: Add Opt-Out Language

Include opt-out language (e.g., “Reply STOP to unsubscribe”) in the first SMS to every new contact.

Step 2: Include Sender Information

Introduce yourself or your company in the first message to new contacts.

Step 3: Avoid SMS-Incapable Devices

Do not send to landlines. Enable Number Intelligence to check numbers before sending and apply temporary DND for non-SMS-capable devices.

Step 4: Avoid Public URL Shorteners

Public shorteners like bit.ly or tinyurl.com can harm deliverability. Carriers like T-Mobile and AT&T flag them as high-risk. Use custom or branded short URLs linked to your domain, limit redirects to one, avoid cloaking, and include full URLs when possible.

Step 5: Register Your Business Profile and Campaign

Register your A2P brand and campaign for enhanced deliverability. For US accounts, use the Trust Center tab once the sub-account country is set to US. Non-US accounts can still follow best practices for high delivery rates. Campaign verification may take up to a week; if not approved, submit a support ticket for escalation.

For web form opt-ins, include separate, optional checkboxes for marketing and non-marketing consent. Do not pre-select them. Add Privacy Policy and Terms & Conditions in the footer. If the phone number field is not mandatory, consent checkboxes are not required.

Step 7: Reference Opt-In Source

In the first message, state how the contact opted in to build trust and transparency.

Frequently Asked Questions

How long does suspension last? Temporary suspensions lift at 00:00 AM UTC the next day.

What if my campaign isn’t approved after a week? Submit a support ticket to escalate the request.

Can I use the system without A2P registration? Yes, but registration improves deliverability and compliance.

Best Practices for SMS Deliverability and Avoiding Restrictions