Automatic SMS after a missed call — a 2026 guide for businesses
How to send an automatic SMS after a missed call: what triggers it in Heilo, sample texts for eight businesses, what not to send and how to test it.
TL;DR: An automatic SMS after a missed call gives the caller a next step: a form, a booking page or your opening hours. In Heilo you set it per number: the SMS goes to a caller who left a voicemail and, if you switch it on, also to one who hung up without leaving a message. Test it before you rely on it.
Why a missed call is an expensive mistake
A caller who doesn't get through may simply call another business. In services this costs you a real job. In e-commerce — a basket finished off at a competitor. In support — your customer's trust.
Even if you call back an hour later, you often face:
- the customer already placed an order with someone else,
- the customer forgot what they wanted,
- the customer picks up but isn't home and doesn't remember the details,
- the customer doesn't pick up because they don't recognize your number.
An automatic SMS helps with several of these: before the customer thinks about the competition, they already have the next step in their hand — a link to a form, calendar, offer page.
What exactly is auto-SMS after a missed call
In Heilo, here's how it works:
- The customer calls and you don't answer.
- With missed-call forwarding set up at your carrier (see how to set up call forwarding to voicemail), the call goes to Heilo and the caller hears your greeting.
- If they leave a message, Heilo sends them your text and, by default, a short call subject (you can choose a shortened quote of the message or nothing).
- If they hang up without a message and you switched on "Send an SMS to the caller when they leave no message", they get your text only.
- You get your own notification with the caller, the topic and a link, if notifications are on.
This isn't "we'll call you back." It is a concrete next step tailored to your line of business.
When the SMS is sent
| Situation | Does the caller get an SMS? |
|---|---|
| Caller left a voicemail | Yes, with your text and, by default, a short call subject |
| Caller hung up without a message | Optional, off by default; the SMS contains only your text |
Heilo has no separate SMS for a busy line, weekends or after hours. Opening hours are set in the number's schedule, so write one text that works at any time.
8 business scenarios — with ready-made SMS copy
Below are concrete scenarios you can adapt. Length, special characters and links change how many SMS segments a text uses, so do not assume every sample fits in one. The links below use example.com as a placeholder.
1. Service salon → link to your booking calendar
Industries: hairdresser, beautician, massage therapist, vet, dentist, physio.
SMS copy:
Hi! Salon Belle here. We can't pick up right now. Book a slot online: example.com/book-belle — see you soon!
Why it works: the customer was about to book — that's why they called. If the phone didn't work out, let them book in your calendar. One click closes the deal.
2. Plumber / electrician / mechanic → contact form with fault description
Industries: technical and emergency services.
SMS copy:
Auto-Service Mat. We couldn't pick up — probably mid-repair. Describe the issue here: example.com/case-mat
Why it works: mechanics don't pick up because they have a wrench in hand. The customer drops the issue in a form — you get specifics instead of "they asked for a callback."
3. Doctor / specialist → online appointment booking
Industries: medical practice, psychologist, lawyer with appointments.
SMS copy:
Dr Nowak's clinic. Reception will call back as soon as possible. You can also book online: example.com/visit-nowak
Why it works: some patients won't wait. Those who can use a website book themselves in minutes — your reception is offloaded from the simplest cases.
4. E-commerce / B2B sales → quote request form
Industries: online store, wholesaler, B2B sales.
SMS copy:
XYZ Wholesale. We can't take your call right now. Drop a quote request (1 minute): example.com/quote
Why it works: B2B sales often start on the phone but move to email. This shortens the cycle: the customer fills the form, you get a brief, you send a quote.
5. Tech support / IT → bug / incident ticket system
Industries: SaaS, IT support, hosting, hardware service.
SMS copy:
Support TechCo. We can't pick up — we're on tickets. Describe the issue (screenshot, log) here: example.com/ticket-techco
Why it works: a bug reported only by voice is hard to diagnose. A form/ticket system lets the customer attach screenshots, logs, exact timestamps. Faster diagnosis.
6. Restaurant / catering → menu page / reservation form
Industries: restaurant, café, catering.
SMS copy:
Verde Restaurant. We missed your call. Menu and reservations: example.com/verde — or call after 3pm.
Why it works: a customer calling at lunchtime wants a table reservation. Instead of waiting for the line to free up, they go to the website, where they often find more info than over the phone.
7. Real-estate agent → listing page / callback form
Industries: real estate, loans, finance.
SMS copy:
Premium Real Estate. I missed your call. Full listings: example.com/listings — leave a contact, I'll call back ready.
Why it works: a customer looking for an apartment wants to see PHOTOS, prices, location. The SMS routes them to a page with the full offer — they narrow it down on their own. By the time you call back, you have a warm lead.
8. Holiday or day off → information page
Industries: anyone who is closed for a few days.
SMS copy:
Studio Belle: we're closed until Monday. Opening hours and contact form: example.com/contact
Why it works: the caller learns when you are back without waiting. Marketing in an automatic reply is covered in the FAQ.
How to set it up in Heilo
Open the number's settings and go to the SMS tab. Turn on "Send SMS to the caller", write your text and choose what Heilo adds below it: a short call subject (the default), a shortened quote of the message, or nothing. Optionally turn on "Send an SMS to the caller when they leave no message"; that SMS contains only your text. Your own alerts are under "Notify me about new calls".
Sender name is optional: up to 11 letters and digits. Without it the SMS comes from Heilo's system number, not the number the customer dialled.
Common mistakes in SMS copy
1. Too long
❌ "Thank you so much for your interest in our company. Unfortunately we are unable to take your call at this time, but we will get back to you at our earliest convenience. In the meantime feel free to visit our website…"
✅ "Salon Belle. We missed you. Book online: example.com/book-belle"
The customer has 3 seconds of attention. Get to the point.
2. No business name
❌ "We missed you. We'll call back."
The customer called three businesses — they don't know who wrote. Always sign with your business name.
3. No specific link
❌ "Check our website."
A homepage link will be gone in 3 seconds. Provide an action link: calendar, form, cart, listing.
4. Overly formal tone
❌ "Dear Customer, we hereby inform you…"
SMS is a personal channel. Write as you would to a friend: direct, with your business name attached.
5. No follow-up
The SMS recovered the contact, but doesn't excuse you from calling back if the customer never got in touch. In Heilo the calls list shows every call, and the "SMS after call" column shows whether the SMS went out.
What NOT to send automatically
- Pricing — especially in services where quotes depend on individual conditions. SMS pricing can scare customers off before the conversation.
- Promises with concrete deadlines — "we'll call back in 15 minutes" only works if you actually do. Otherwise you build expectations and break them.
- Sensitive data — auto-SMS is a public channel; don't put medical, financial, or legal data in it.
What it costs
The caller SMS is part of Heilo's business voicemail. Plans and prices are on the pricing page. To judge whether the SMS helps, count how many requests arrive through the link you include.
Summary
An automatic SMS after a missed call gives a caller you missed a clear next step. Key points:
- A specific link beats a polite "we'll call back"
- Business name as the sender
- Short, to the point, single CTA
Set it per number, test it, and check the calls list for anyone who still needs a callback.
See Heilo business voicemail. Plans and prices are on the pricing page.
FAQ
Can the customer reply to the auto-SMS?
Not if the SMS comes from your business name as an alphanumeric sender: that channel is one-way (Twilio documentation, checked 20 October 2026). If you want an answer, give a working phone number or a link to a form in the text.
Is this spam?
Keep a message about the customer's call separate from advertising. A call alone does not automatically mean consent to marketing messages, so assess the content, purpose and legal basis of what you send under the rules that apply to your company.
What about GDPR?
The SMS content must comply with your privacy policy. Heilo gives you the tools to inform the caller (a notice, your own wording, a call label). Your company, as the data controller, provides the legal basis and meets the duty to inform. Heilo uses the subprocessors listed in its terms, including Twilio (telephony, a US company), Supabase (database in the EU), Vercel (hosting) and Google Gemini (transcription and analysis).
Can I have different copy for different customers?
You can write a separate text for each business number. Within one number there is one text, not one per scenario.
Does the SMS reach every caller?
Usually not to landlines, which can't receive SMS, so the send fails. The "SMS after call" column in your calls list shows whether each SMS went out and, if it failed, the reason given by the carrier.
How long does setup take?
Write one text per number, choose what Heilo adds below it (a short call subject, a shortened quote of the message, or nothing), save, and then test it with a call from another mobile.
