What is CASL?

CASL (Canada's Anti-Spam Legislation) is Canadian federal law regulating commercial electronic messages, enacted in 2014. It's widely considered one of the world's strictest anti-spam laws, requiring prior consent before sending commercial email-the opposite of CAN-SPAM's opt-out approach. CASL applies to any commercial electronic message sent to or accessed from a computer in Canada.

The law distinguishes between express consent (explicit opt-in that doesn't expire) and implied consent (inferred from relationships with time limits). Express consent requires clear, affirmative agreement; implied consent exists temporarily based on transactions or inquiries. CASL prohibits pre-checked consent boxes and requires documentation proving consent was obtained.

CASL also regulates software installation, altered transmission data, and false/misleading representations in electronic messages-it's broader than pure email law. Enforcement comes from the CRTC (Canadian Radio-television and Telecommunications Commission) with penalties reaching $10 million per violation for businesses. CASL's strictness makes it a de facto global standard for organizations that can't guarantee excluding Canadian recipients from their lists.