SMS API in Canada 2026: CASL and the Express-Consent Rule

CASL sets a high consent bar

An SMS API in Canada operates under CASL (Canada's Anti-Spam Legislation), one of the strictest anti-spam laws in the world. CASL applies to SMS, per the CRTC, and its core rule is demanding: you can't send a commercial text to a Canadian recipient without their consent, and the standard for express consent is high. It must be proactive. The recipient takes an action to opt in. Pre-checked boxes don't count, because consent can't be assumed. There are narrow implied-consent exceptions, but the default is a genuine, documented, opt-in. Miss it and CASL's penalties are severe: administrative monetary penalties reach CAD 1 million per violation for an individual and CAD 10 million for a business (CRTC, 2026). So Canada is a consent-first market where the consent has to be real.

Here's what CASL requires, the express-vs-implied distinction, and how to send commercial SMS in Canada legally.

SMSRoute's published route page for Canada lists direct-carrier delivery via Rogers, Bell, Telus from $0.015/message, with 89ms median submission and 98.9% delivered success (smsroute.cc route pages, 2026). For A2P (application-to-person) messaging, using a direct route via an aggregator can improve deliverability.

Express consent, the CASL way

Express consent is the standard, and CASL is specific about it. The recipient must take a proactive action to opt in: signing up, checking an unticked box, texting a keyword. Pre-filled checkboxes are explicitly not allowed, per CRTC guidance, because they suggest rather than obtain consent. One upside: once you have valid express consent, it doesn't expire on a timer — you can send until the person opts out. Implied consent exists but only in narrow situations, like an existing business relationship, so don't rely on it as your default.

Sending compliantly in Canada

1. Get proactive express consentAn unticked checkbox, a keyword opt-in, an explicit sign-up. The recipient acts to consent — never a pre-filled box. Use clear opt-in wording and log it.
2. Document everythingRecord who consented, when, and how. CASL enforcement puts the burden of proof on the sender, so unprovable consent is treated as none.
3. Provide clear identification and opt-outCommercial messages must identify the sender and offer a working unsubscribe. Honor opt-outs promptly.
4. Distinguish transactional from commercialOTPs and transactional messages rest on the relationship; CASL's consent rules bite hardest on commercial marketing — the compliance distinction matters.

Sending to Canada in practice

SMSRoute is a no-KYC SMS API with crypto billing (BTC, ETH, USDT, XMR, LTC, and SOL) serving the international route to Canada, with live pricing on the send SMS to Canada page. For transactional and OTP traffic — resting on the service relationship rather than CASL marketing consent — the route delivers to Canadian users reliably. Canada is a well-connected market where the discipline is consent, not routing exotica. When sending, ensure phone numbers are in international format (E.164) to avoid carrier filtering. Transactional messages include password resets or payment confirmations; promotional offers are commercial. This distinction determines whether CASL consent is required.

The honest framing: CASL express consent is your obligation to obtain and document, whatever provider you use; we deliver the messages your compliant process approves. For transactional and OTP, the relationship implies the basis. For commercial marketing, get proactive express consent (no pre-checked boxes), document it, and honor opt-outs. And note Canada is distinct from the US — CASL is stricter than TCPA, so US consent practices don't automatically satisfy it. Treat Canada as its own market, get the express consent right, and delivery is straightforward. For how this market fits the wider picture, see the global SMS compliance guide.

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