Twilio has no missed-call button. It has parts.
You read that a Twilio number can text missed callers for pennies. It can, but Twilio sells building blocks, and its documentation, checked in September 2026, has no ready-made missed-call text back. The closest thing is Studio, its drag-and-drop flow builder. Below is that build from Twilio's docs, then the paperwork that decides whether your texts arrive.
Six widgets, wired in order.
Twilio's call-forwarding tutorial covers the first and last steps. The middle comes from the widget reference pages for Connect Call To, Split Based On, Send Message, and Make HTTP Request.
- 01
Trigger. Create a new flow in the Studio dashboard. The canvas starts with the Trigger widget; wire its Incoming Call transition onward.
- 02
Connect Call To. Single Number, your cell in E.164 format (+1 and ten digits). Timeout defaults to 30 seconds. Set it shorter than your cell takes to reach its own voicemail, or the voicemail picks up and Studio counts the call as answered.
- 03
Split Based On. Test the Connect Call To widget's DialCallStatus. "completed" means you picked up, so end there. Everything else (no-answer, busy, failed) falls to No Match and continues.
- 04
Say/Play. One sentence telling the caller a text is coming.
- 05
Send Message or Make HTTP Request. Send Message texts the caller a fixed body. Make HTTP Request instead POSTs the call to your own code, which must answer within Studio's 10-second limit.
- 06
Publish, then attach. Publish the flow. In the console, open the number under Numbers & senders, then the Voice configuration, choose Studio Flow, pick this flow, and save.
The status values are on Twilio's <Dial> reference. Last, point your published number's unanswered calls at the flow. From a cell, that's a carrier code: on AT&T or T-Mobile, *61* plus the Twilio number for no answer; on Verizon, *71 plus the number.
What the Send Message version texts
158 characters, identical for every caller
The flow takes an afternoon. The paperwork decides if it sends.
A published flow on an unverified number sends nothing to a US phone. Which paperwork you file depends on the number you bought.
Toll-free number
Twilio's onboarding guide says a toll-free number can't text the US or Canada until it's verified. The verification fields include your business name and website, a use-case summary, a sample message, how people opt in (with images showing it), and monthly volume. Every business type except a sole proprietor gives a registration number.
Local (10DLC) number
A local number needs A2P 10DLC registration: a Brand for the business, then a Campaign describing the messages and the opt-in and opt-out handling. A tax ID is required except for sole proprietors. Unregistered texts to US numbers are blocked with error 30034.
STOP handling comes free: per Twilio's opt-out docs, a STOP reply puts the sender on a block list, and toll-free numbers always unsubscribe on STOP. Who you may text, and when, is covered in Twilio's messaging policy and the FCC's consumer guide; ask your own counsel how they apply.
The managed agent runs the same flow, plus a voicemail.
Nothing proprietary sits in the call path. The console creates a Studio flow on the number it provides: ring your cell for 15 seconds, split on the dial status, and on anything but a pickup say “Sorry, Saltbox Garage Doors missed your call. Please leave a short message after the tone, and we'll get back to you.” A Record Voicemail widget takes up to 90 seconds with Twilio's transcription on. Then a Make HTTP Request widget POSTs the caller's details, the recording, and the STIR/SHAKEN result to the agent, which accepts at once and works afterward, inside Studio's 10-second window. It waits for the transcript before it writes.
Because the flow takes a voicemail, the first text can answer what the caller said. A caller who leaves nothing gets a question tuned to your trade, like the two below, and the answer comes in the thread. What it adds over a fixed body is screening, your hours, a name when the caller is in your HubSpot, and a second model checking the draft against your prices and links. The spoken line doesn't promise a text: a screened caller never gets one, and anyone ringing after 8 pm is texted at 8 am. A caller who hangs up during the ring still reaches the agent. The managed flow's ring is fixed at 15 seconds, and your cell's own voicemail picking up counts as answered, so the setup test call is where that gets caught.
240 characters
237 characters
| Your Studio flow | Managed agent | |
|---|---|---|
| Who builds the flow | You, in the Studio canvas | Built and published for you on the number provided |
| Carrier verification | You file it and answer the reviewer | Filed under your business's identity for you; typically about three business days |
| Robocalls and landlines | Texted like anyone else unless you code a filter | Screened out before anything is drafted |
| Calls at 11 pm | Texted at 11 pm unless you add a time split | No text from 8 pm to 8 am; you get any voicemail at once, and the caller is texted at 8 am |
| The caller replies | Goes nowhere until you wire the Incoming Message trigger | Answered in the same thread from your prices and FAQ |
| Wording | One fixed body for every caller | Written per call, then checked against your configured facts |
| Cost | Twilio usage and your time | $249/mo, no setup fee, plus AI usage and phone line costs, typically $20–40 a month |
The number sits on its own Twilio sub-account and ports out with you if you leave. A question your information doesn't cover gets no guess: the agent texts that someone will get back to them, and a Slack alert tells you to call them back. The full sequence, from signing to the test call, is in the setup guide.
If one fixed text covers your callers, keep your money.
Build the Studio version if you're comfortable in the Twilio console, most callers want the same booking link, spam calls are rare, and you'll answer replies yourself. It costs Twilio usage and an afternoon, and a fixed text that names you, admits it's automated, and carries the opt-out line is a fair message.
The managed version earns its fee when replies pile up unanswered or robocalls eat your texts. At $249 a month plus usage at its $40 high end, and an example job worth $240, it has to bring back 2 jobs a month that the fixed text would have lost. The pricing page has the full breakdown. Everything else about the agent is on the missed-call text back page, and sample wording for each trade is on the templates page.
