n8n Twilio Missed Call SMS Workflow (AU) — Webhook Auto Reply

Never miss a lead: auto-text every missed caller from your AU business number

This n8n workflow sends an SMS to every missed caller in Australia—so when calls go unanswered, your business immediately replies with a short voice message and then texts the caller with your name and “Reply STOP to opt out”. Built for AU mobile formatting, 12-hour dedupe, and compliant STOP handling.

What this workflow does

• Missed call webhook → voice reply (TwiML): Twilio triggers the missed-call webhook when a call is unanswered. The workflow responds with a short voice message using TwiML.
• AU number normalisation & filtering: It converts AU numbers into +614xx format (e.g., 04xx → +614xx), skips landlines, and deduplicates within 12 hours so the same person isn’t spammed.
• SMS follow-up from your business number: Twilio sends an SMS to the caller, including your business name and the line “Reply STOP to opt out”.
• STOP/START compliance: Inbound SMS replies are recorded so opted-out numbers are never texted again (and can resume with START).

Use cases

• Australian tradies (plumbers, electricians, builders) who miss calls while on-site.
• Small service businesses that need a fast “we’ll call you back” SMS for every missed inbound call.
• Teams using n8n to automate customer follow-up without manual outreach.

Technical details

• n8n nodes / stack: code, webhook, sticky note, http request, respond to webhook.
• Twilio integration: Voice missed-call webhook and Messaging webhook for inbound SMS.
• HTTP Basic Auth (Send SMS → Twilio): User = Twilio Account SID, Password = Auth Token.
• Requirements: Twilio account with an AU mobile number and an n8n instance reachable from the internet.

Setup highlights

Configure businessName, smsFrom (your Twilio AU number in +61 format), and your twilioAccountSid in Decide. Then activate and point your Twilio Voice webhook to /webhook/missed-call and Messaging webhook to /webhook/sms-inbound. Forward unanswered calls from your mobile to the Twilio number (carrier codes 61*, 67*, 62*; cancel with ##004#). Setup typically takes about 15–20 minutes.

Customization: Edit the message text and the dedupe window in Decide’s CONFIG block.