### Answer To send SMS from Retell during a call, you'll use Retell's Send SMS tool within your agent configuration [(1) ]() . Here's the setup: ## Prerequisites Your phone number must have SMS enabled through the A2P application process, or you can send from an SMS-approved Retell number (which bypasses A2P) [(2) ]() [(1) ]() . ## Setup Steps 1. Add the Send SMS tool to your single or multi-prompt agent [(1) ]() 2. Choose sending number : - **SMS-approved Retell number**: Uses Retell's pre-approved pool, no A2P needed, but uses a preset template you cannot customize - **Agent's associated number**: Sends from your bound number (requires SMS enabled via A2P) 3. Configure SMS content : - If using your number: Write a prompt for the agent to infer content, or use static text with dynamic variables - If using Retell's approved number: Content is a preset template, not editable 4. **Set destination**: Defaults to caller's number, or specify a static/dynamic number like

{{customer_phone}}

5. Optional settings : - Enable "Talk while waiting" for the agent to speak while sending - Enable "Speak after sending message" to confirm delivery ## GoHighLevel Integration For triggering SMS through GoHighLevel workflows during calls, you can use webhooks to connect Retell call events to GHL automation workflows that send SMS [(3) ]() [(4) ]() . The Retell webhook sends call data to GHL, where you map specific fields into custom fiel

ds before triggering the SMS action .

​ To learn more, see the sources I considered: [[1] Send SMS](https://docs.retellai.com/build/single-multi-prompt/send-sms) [[2] Send & receive SMS](https://docs.retellai.com/deploy/enable-sms) [[3] Discord message from @ogma972 on 2026-01-08](https://discord.com/channels/1186424376300679209/1186462578310910112/1458897370225053807) [[4] Discord message from @knightflash2000 on 2026-01-08](https://discord.com/channels/1186424376300679209/1186462578310910112/1458939549223882845) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer When sending from an SMS-approved Retell number, the message content is strictly a preset template provided by Retell — you cannot customize the text or use a prompt [(1) ]() [(2) ]() . If you need to customize the SMS content, you must use your agent's associated number instead, which requires completing the A2P application process to enable SMS capabilities . With your own SMS-enabled number, you can: - Write a prompt to let the agent infer the SMS content - Use static SMS content with dynamic variables supported [(1) ]()

​ To learn more, see the sources I considered: [[1] Send SMS](https://docs.retellai.com/build/single-multi-prompt/send-sms) [[2] Send & receive SMS](https://docs.retellai.com/deploy/enable-sms) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer Here are your alternatives if A2P approval isn't working: ## 1. Use SMS-Approved Retell Numbers (No A2P Required) Send from Retell's pool of SMS-approved numbers during active calls [(1) ]() [(2) ]() . This bypasses A2P entirely—no setup or approval steps needed. The message uses a preset template provided by Retell that you cannot customize, but you can start sending immediately [(1) ]() . ## 2. Custom Function with Your Own SMS Provider Create a custom function that calls your existing SMS provider's API (Twilio, Telnyx, etc.) directly [(3) ]() [(4) ]() . This lets you send SMS with full customization using your provider's approved credentials, triggered by the agent during calls. ## 3. Webhook-Based SMS via External Automation Use Retell's webhooks to trigger SMS through external platforms like Make, Zapier, or GoHighLevel [(5) ]() . Configure a webhook to fire during or after calls, then route to your automation platform which sends the SMS using your provider's integration [(4) ]() . ## 4. Post-Call Email Instead Switch to email for post-call summaries using the

call_analyzed

webhook . After each call, you receive a webhook with the call summary to your server, where you can send emails or update your CRM without SMS restrictions . The custom function or webhook approaches give you the most flexibility while working around A2P approval issues.

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

​ To learn more, see the sources I considered: [[1] Send & receive SMS](https://docs.retellai.com/deploy/enable-sms) [[2] SMS Node](https://docs.retellai.com/build/conversation-flow/sms-node) [[3] send_sms tool doesnt recognize twilio A2P](https://discord.com/channels/1186424376300679209/1391669424620310618) [[4] SMS is not sent.](https://discord.com/channels/1186424376300679209/1460659178120024096) [[5] GHL + Make + Retell](https://community.retellai.com/t/ghl-make-retell/806) ​