Canada's Anti-Spam Legislation, in force since July 1, 2014 — requiring consent before sending commercial electronic messages, with sender identification and a working unsubscribe.

What is the difference between express and implied consent under CASL?

Express consent is a clear proactive opt-in that never expires until withdrawn; implied consent arises from relationships like a purchase (two years) or inquiry (six months) and expires on schedule.

Growth Marketing Glossary

CASL (Canada's Anti-Spam Legislation)

C·A·S·Lnoun (law)

Ask before you email — Canada's opt-in law, with penalties that make a sloppy list an expensive habit.

Schematic — consent before the commercial message

Term: CASL (Canada's Anti-Spam Legislation)
Is: Canada's Anti-Spam Legislation
In force: July 1, 2014
Model: Opt-in consent, express or implied

Forms & parts of speech

CASL · noun

Canada's opt-in email law.

"Under CASL the burden is yours - prove consent for every Canadian address or don't press send."

Definition in plain terms

CASL — Canada's Anti-Spam Legislation, in force since July 1, 2014 — is the law governing commercial electronic messages sent to or from Canada. Its core demand is consent before sending: unlike the US CAN-SPAM ACT, which lets you email until someone opts out, CASL requires permission before the first message arrives, making Canada an opt-in jurisdiction with some of the toughest anti-spam penalties anywhere — administrative monetary penalties run to $10 million per violation for organizations.

The mechanics

CASL covers commercial electronic messages broadly — email, SMS, and direct messages with commercial purpose — and rests on three obligations: consent, identification, and unsubscribe. Consent comes in two flavors. Express consent is a clear opt-in (a ticked box the user ticked, a signup with notice of what they will receive) and never expires until withdrawn. Implied consent arises from defined relationships — an existing business relationship from a purchase (valid for two years), an inquiry (six months), or a conspicuously published business address relevant to the message — and it expires, which means list hygiene must track consent type and date per contact. Pre-checked boxes do not count; the recipient must act. Every message must identify the sender with contact information and carry a working unsubscribe honored within 10 business days. Enforcement runs through the CRTC alongside the Competition Bureau and Privacy Commissioner, and the burden of proving consent sits with the sender — which makes records the compliance asset: when, how, and for what each address consented. For marketers the operational consequences are concrete: bought lists are radioactive, lead-gen forms need consent language designed in, COLD EMAIL to Canadian addresses needs a qualifying implied-consent basis, and consent records belong in the CRM, not in folklore.

When it matters

CASL matters to anyone with Canadian addresses on a list — which, for most North American senders, is everyone, often without knowing it. It matters most at acquisition moments (form design, lead imports, list merges) where consent is either captured properly or lost forever, and at the two-year expiry horizon of implied consent, where unconverted contacts quietly become unlawful sends. The discipline is to capture express consent wherever possible (it never expires), timestamp every consent with its basis, segment Canadian traffic where evidence is thin, and treat the unsubscribe as sacred. Senders who built for CASL discovered the side effect deliverability teams already knew — consented lists perform better everywhere. (General information, not legal advice.)

Worked example. A US software firm imports a partner's conference list and blasts a promotion, unaware a fifth of the addresses are Canadian. Several recipients complain to the CRTC's spam reporting centre, and the firm cannot produce consent evidence for a single Canadian address - the list was bought trust, not earned permission. Counsel's remediation is a rebuild: Canadian contacts suppressed until re-permissioned through a campaign offering genuine value for an explicit opt-in, forms gain CASL-compliant consent language with timestamps written to the CRM, implied-consent contacts get expiry tracking with conversion-to-express prompts, and list imports now require consent provenance before a single send. The re-permissioned Canadian segment ends up a third the size and twice the open rate - the law forced the firm into the list it should have built anyway.

Failure modes to watch. Bought or borrowed lists with no consent provenance; pre-checked boxes that fail the proactive-consent test; implied consent left untracked past its two-year expiry; no per-contact consent records when the burden of proof is the sender's; and treating CASL as Canada's CAN-SPAM when one is opt-in and the other opt-out.

Synonyms & antonyms

Synonyms

CASLCanada's Anti-Spam LegislationCanadian anti-spam law

Antonyms

CAN-SPAM (opt-out model)unsolicited bulk email

Origin & history

Canada's Anti-Spam Legislation passed in December 2010 and came into force on July 1, 2014, with a 36-month transition deeming implied consent for existing relationships. Enforced by the CRTC with the Competition Bureau and Privacy Commissioner, it established one of the world's strictest opt-in regimes for commercial messaging.

Etymology: source.

Usage trends

Search interest for this term over the last five years:

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Common questions

What is CASL?: Canada's Anti-Spam Legislation, in force since July 1, 2014 — requiring consent before sending commercial electronic messages, with sender identification and a working unsubscribe.
What is the difference between express and implied consent under CASL?: Express consent is a clear proactive opt-in that never expires until withdrawn; implied consent arises from relationships like a purchase (two years) or inquiry (six months) and expires on schedule.
How is CASL different from CAN-SPAM?: CAN-SPAM allows emailing until the recipient opts out; CASL requires permission before the first message — and puts the burden of proving that consent on the sender.

Related tools & calculators

toolCAC calculator
toolLTV:CAC calculator

Resources & people to follow

referenceCRTC — Canada's Anti-Spam Legislation
referenceCRTC — guidance on implied consent
referenceRGM analysis — timestamp every consent with its basis; implied consent is a countdown, not a status

Curated, non-competitor resources verified per term.

Related training

modulePerformance marketing

Disciplines

Areas of marketing where casl is a core concern:

Performance marketingGrowth strategy

Sources

trendsGoogle Trends — "casl compliance"