Texting back missed callers: CASL and TCPA basics

Someone calls, you're under a sink, the call goes to voicemail. A quick text back (“Sorry we missed you, what do you need?”) is one of the simplest ways not to lose that job. Here is what the rules say about it in Canada and the US.

Canada: CASL

Canada's Anti-Spam Legislation (CASL) covers commercial electronic messages, and texts count. Three things matter for a text-back:

• Consent. When someone contacts your business with an inquiry, CASL gives you implied consent for six months from that inquiry (s. 10(10)(e)). Some messages, like a requested quote or estimate, are exempt from the consent rule (s. 6(6)).
• Identification. Each message has to identify the sender and include contact details. The CRTC's regulations ask for a mailing address plus a phone number, email or web address; in a text this can be a short link to a page with those details.
• Unsubscribe. Each message needs a working opt-out, and opt-outs have to take effect within 10 business days (s. 11(3)). Honouring STOP right away is the safe habit.

What CASL doesn't allow is using that number later for promotions the person never asked for once the six months are up, or texting numbers that never contacted you.

United States: TCPA

Under the Telephone Consumer Protection Act, texts are treated like calls. Automated texts to a cell phone generally need the person's prior express consent, and marketing texts need prior express written consent (47 CFR § 64.1200). A one-off reply to someone who just called you is very different from a marketing campaign, but:

• keep the text-back about their call: no promotions;
• honour opt-outs sent by any reasonable means, such as “stop”, “cancel” or “unsubscribe”. The FCC's 2024 order (FCC 24-24) took effect April 11, 2025, with a 10-business-day deadline to honour them;
• avoid late-night texts. The federal rules limit telephone solicitations to 8 a.m. to 9 p.m. local time, and some states are stricter;
• business texting from US numbers also needs carrier registration (10DLC) through your texting provider.

A good text-back, and a bad one

What Towntide Voice does

• It only texts numbers that called or texted the business in the last 180 days. There's no way to upload a list or send a campaign.
• Every customer text starts with the business name and ends with “Reply STOP to opt out.”
• STOP, UNSUBSCRIBE, CANCEL, END and QUIT opt the number out at once, cancel anything still scheduled, and send one confirmation. START opts them back in.
• Quiet hours: customer texts that would go out late at night wait until morning. Emergency alerts to the owner's own phone are never held.
• It never makes outbound AI calls.