Is missed-call text-back legal?

You missed a call while you were under a house, and a few seconds later the caller gets a text: "Sorry we missed you, what's going on?" Before you switch that on, most owners ask one fair question: can that text get me sued or fined?

The short answer is that a one-off text to someone who just called you is one of the lower-risk texts a business can send. "Lower-risk" still isn't "automatically fine", though. Three sets of rules apply. In the US, that's the TCPA (federal law) plus A2P 10DLC registration (a carrier requirement, not a law). If you serve Canada, it's CASL. This article walks through each one, points out where the rules are honestly gray, and ends with a checklist.

Not legal advice. We build and test automations; we're not lawyers. This is a plain-English summary of primary sources, checked on October 27, 2026. Rules change and state laws differ. If texting is a big part of how you sell, spend an hour with a lawyer who handles TCPA or CASL work.

The short answer

US: Text only people who just called you. Keep the first text about their call, not a promotion, and make it easy to reply STOP. Don't run a "text everyone who ever called" campaign without written consent. Register for A2P 10DLC before you send anything from a local number.
Canada: A text that invites someone to book is probably a "commercial electronic message" under CASL. Someone who called you to ask about a job most likely gives you implied consent for six months. Every such text must still say who you are and offer an unsubscribe.
Both: Keep a record of who called, when, and what you sent.

Why a missed call sits in a gray zone

Most texting guidance assumes the customer texts first. CTIA is the wireless industry group whose messaging principles the carriers follow. Its Messaging Principles and Best Practices (May 2023) put messages into three buckets:

Type	CTIA's description	Consent CTIA expects
Conversational	The consumer texts first and the business responds with relevant information	Implied: "no additional permission is expected"
Informational	The consumer gave you their number and asked to be contacted (reminders, alerts)	Express consent (verbal, form or text)
Promotional	Sales or marketing content	Express written consent

A missed-call text doesn't fit neatly into any of these. The customer started the contact, but by calling, not texting, so your business sends the first text. The FCC has held that a one-time text sent immediately in response to a consumer's request, containing only what they asked for, doesn't violate the TCPA. That comes from its 2015 Omnibus Declaratory Ruling (FCC 15-72, on "on-demand" texts). In that ruling the consumer's request was itself a text. A missed call isn't an explicit request for a text, but it's close. The safest reading is to treat the missed call as permission to answer that one inquiry, and nothing more.

In practice, that means:

Respond only to the call itself. Something like "Sorry we missed you, how can we help?" is fine. "Sorry we missed you, and 20% off duct cleaning this month!" turns the text into a promotion. CTIA notes that even adding a coupon code to an informational text "may place the message in the promotional category", and promotional texts are the ones the FCC and CTIA expect written consent for.
One text, then wait. If they reply, you're in a conversation they chose. If they don't, don't chase them with a sequence.
Don't reuse the number for marketing. They asked about a furnace, not your newsletter.

United States: the TCPA

The TCPA is the Telephone Consumer Protection Act, 47 U.S.C. § 227. The FCC's rules for it are in 47 CFR 64.1200. The points that matter for a text-back:

Texts count as calls. The FCC has long treated text messages as "calls" under the TCPA (restated in the 2015 ruling above). Its consumer guide says autodialed texts to a mobile phone need prior consent unless they're for emergencies. It also says commercial texts need written consent, while consent for informational texts may be oral.

The "autodialer" question is narrower than it used to be, but don't lean on it. In Facebook v. Duguid (2021), the Supreme Court held that equipment is only an "automatic telephone dialing system" if it uses a random or sequential number generator. A text-back system arguably isn't one, but some states have their own laws. Florida's (§ 501.059), for example, covers sales calls and texts made with "an automated system for the selection and dialing of telephone numbers", a definition that doesn't mention a random or sequential number generator. Build as if consent matters either way.

Getting it wrong is expensive per message. The TCPA lets the person who got the text sue for actual losses or $500 per violation, whichever is greater. A court can triple that to $1,500 if the violation was willful or knowing (47 U.S.C. § 227(b)(3)). Those amounts are per text, which is why a sloppy follow-up sequence is the risky part, not the first reply.

STOP has to work, including replies other than "STOP". Under § 64.1200(a)(10):

Replies of "stop", "quit", "end", "revoke", "opt out", "cancel" or "unsubscribe" automatically count as revoking consent. So does any other reply that a reasonable person would understand as "stop texting me".
Revocations must be honored within 10 business days.
You may send one confirmation text, with no marketing in it. It's presumed fine if it goes out within five minutes.

This rule is changing on November 25, 2026. An FCC order published October 26, 2026 lets senders designate an exclusive, clearly disclosed way to opt out, such as replying with the standard words. Either way, the simple path is the same: say "Reply STOP to opt out" and make sure it works.

Quiet hours. The FCC bars telephone solicitations before 8 a.m. or after 9 p.m. local time (§ 64.1200(c)(1)). An instant reply to a 10 p.m. caller isn't a solicitation in the usual sense, but hold non-urgent follow-ups until morning.

AI voice callbacks are a separate question. The FCC ruled in 2024 that AI-generated voices count as "artificial" under the TCPA, so an AI agent that dials out needs its own consent analysis.

United States: A2P 10DLC (a carrier rule, not a law)

Even a perfectly legal text won't get delivered if you skip this step. Twilio's A2P 10DLC docs explain it this way: US carriers treat messages sent from a platform like Twilio as application-to-person traffic. Anyone texting US numbers that way from a regular 10-digit number must register a brand (your business) and a campaign (what you send and how people opt in).

Twilio's published fees, checked October 27, 2026:

Fee	Amount	Source
Brand registration (one-time)	$4.50	Twilio brand registration docs
Secondary vetting, Standard brands only (one-time)	$41.50	Same
Campaign vetting (one-time, non-refundable)	$15	Twilio campaign vetting FAQ
Monthly campaign fee	$1.50 (low-volume mixed) to $10 (most standard use cases)	Twilio A2P 10DLC pricing and fees

According to Twilio's vetting FAQ, campaign vetting can take up to about five business days for standard use cases. Describe the campaign literally, e.g. "Customers call our business number. If we miss the call, we send one text asking how we can help. Reply STOP to opt out.", and give sample messages that match what you'll actually send.

Canada: CASL

Canada's Anti-Spam Legislation covers texts, not voice calls. The CRTC's CASL FAQ confirms both points. It also says messages sent into Canada from abroad have to comply, so a US shop serving Windsor or Vancouver is covered too.

Is your text-back a "commercial electronic message"? If it encourages someone to buy, for example "you can book by text", assume yes. The ISED texting guidance says CASL is technology-neutral and applies to commercial texts.

Consent. Under CASL section 10(10)(e), an inquiry made to your business in the previous six months counts as an "existing business relationship", which gives you implied consent. A purchase in the last two years does the same. A call asking about a furnace repair is a reasonable fit. Separately, section 6(6)(a) exempts a message that solely provides a quote the person asked for from the consent requirement. That exemption doesn't cover the identification and unsubscribe rules.

What every commercial text must include (section 6(2) and the CRTC FAQ):

Who is sending it (your business name).
A way to contact you. The CRTC FAQ says that when a text is too short to fit everything, you can link to a page that has it.
An unsubscribe mechanism. For SMS, the CRTC accepts replying "STOP" or "Unsubscribe". Under section 11, you must act on the request within 10 business days, and the unsubscribe address has to stay valid for 60 days after you send.

Penalties. The CRTC FAQ lists administrative monetary penalties of up to $1 million per violation for individuals and $10 million for businesses. Those are maximums, not typical fines.

Delivery in Canada. Twilio's Canada SMS guidelines say Canadian carriers "enforce strict filtering" on application-to-person texts, and Twilio recommends short codes or verified toll-free numbers for the best delivery. Number registration rules vary by provider, so check yours.

A practical checklist

Before you turn it on:

US: A2P 10DLC brand and campaign approved, with a campaign description that matches what you'll actually send.
Text only numbers that just called you. Skip blocked and anonymous callers.
One text per caller per window (for example, 12 hours), so a caller who rings three times gets one text, not three.
First text: business name, a reference to their call, a question, and "Reply STOP to opt out." No offers or coupons.
STOP, END, CANCEL, QUIT, UNSUBSCRIBE, REVOKE and "opt out" all block future texts. Plain-English replies like "don't text me" must be honored too, so catch them automatically or have someone review replies.
Opt-outs honored well within 10 business days (ideally instantly), and at most one confirmation text.
Non-urgent follow-ups held until after 8 a.m. local time.
Canada: business name and contact info (or a link to them) in the text, a working unsubscribe, and a callback window under six months.
Never move these numbers into a marketing list without separate written (US) or express (Canada) consent.
Log every call, text and opt-out with timestamps, and keep the log.
Emergencies: a text never replaces your on-call process. Gas-smell callers should get safety instructions, not a booking link.

How our recipe handles this, and what it doesn't

Our missed-call text-back recipe (n8n + Twilio + Jobber) covers several checklist items: it texts only unanswered callers, at most once per caller per 12 hours, skips anonymous callers, and gives gas-smell callers safety instructions instead of a booking.

Since October 27, 2026, its greeting ends with "Reply STOP to opt out." Twilio's default opt-out handling covers the standard keywords. Twilio's docs list STOP, UNSUBSCRIBE, END, QUIT, STOPALL, REVOKE, OPTOUT and CANCEL. The workflow also catches common plain-English requests such as "please stop texting me" or "take me off your list": it sends one confirmation with no marketing, stops all automatic texts to that number, and passes any later texts from that number to the office. A fixed phrase list can't catch every wording, so still skim replies now and then. And it was tested against mock versions of Twilio and Jobber, not a live account. Run your own test calls before you rely on it.

For costs and how the flow works step by step, see HVAC missed call text back, priced out.

Sources

All checked October 27, 2026.

FCC, Stop Unwanted Robocalls and Texts (consumer guide, last reviewed Feb 27, 2026).
47 CFR 64.1200 (eCFR, current text): revocation (a)(10)–(12), quiet hours (c)(1).
47 U.S.C. § 227 (TCPA), including statutory damages in (b)(3).
FCC, Omnibus Declaratory Ruling and Order, FCC 15-72 (2015): texts are calls; on-demand texts.
FCC, Enhancing the Ability of Consumers To Control the Robocalls, 91 FR 67214 (Oct 26, 2026; effective Nov 25, 2026).
FCC, Declaratory Ruling FCC 24-17 (2024): AI-generated voices.
Supreme Court, Facebook, Inc. v. Duguid, No. 19-511 (Apr 1, 2021).
Florida Statutes § 501.059 (Florida Telephone Solicitation Act).
CTIA, Messaging Principles and Best Practices (May 2023). Industry guidance, not law.
Twilio, A2P 10DLC pricing and fees, A2P 10DLC Brand Registration, Campaign Vetting FAQ, Advanced Opt-Out and Canada SMS guidelines. Vendor documentation.
CRTC, Frequently Asked Questions about CASL.
Justice Laws, S.C. 2010, c. 23 (CASL): sections 6, 10 and 11.
ISED, Texting for good client relations.