n8n Twilio Missed Call Textback to SMS + Slack Alert

Turn missed Twilio calls into instant SMS + Slack alerts

This n8n workflow listens to Twilio Voice status webhooks, detects missed calls, automatically sends a Twilio SMS text-back (different wording for business hours vs after hours), logs every event in Google Sheets, and notifies your front desk in Slack.

What this workflow does

• Receives a POST webhook from Twilio Voice “Call Status Changes” (status callbacks) for each call.
• Checks the call status and ignores answered calls, continuing only for no-answer, busy, or failed outcomes.
• Extracts key details such as the patient phone, clinic phone, Call SID, and the timestamp.
• Determines whether the current time falls within your defined business hours.
• Sends an SMS text-back to the caller using the business-hours or after-hours message template.
• Appends a log entry to Google Sheets including timestamp, caller, call status, business-hours flag, and Call SID.
• Posts an alert message to a Slack front-desk channel so staff can follow up.
• Returns a success JSON response to the Twilio webhook request.

Use cases

• Clinics that want missed-call follow-up via SMS without manual dialing.
• Front desks that need real-time Slack notifications for no-answer, busy, and failed calls.
• Operations teams who require an auditable Google Sheets log for every missed-call event.

Technical details

• n8n nodes: webhook, if, set, code, slack, twilio
• Twilio: uses Twilio credentials (Account SID and Auth Token) for SMS sending
• Google Sheets: OAuth2 logging (e.g., Timestamp, Patient Phone, Call Status, Business Hours, Call SID)
• Setup: configure your Twilio phone number’s Voice status callback URL (POST) to the workflow’s production webhook