The Canadian Anti-Spam Legislation (CASL), in force since July 2014, is one of the strictest anti-spam laws in the world. It prohibits sending commercial electronic messages (email, SMS, automated voice message) without prior express consent of the recipient, with limited exceptions. The maximum penalty is $10 million per incident for a business and $1 million for an individual. More importantly, CASL provides a private right of action — any recipient can sue civilly the sender of non-compliant emails. For invoicing, the rule is clear: invoices themselves (existing contractual relationships) are exempt, but all marketing around invoicing (newsletters, promotions, cart abandonment follow-up) must comply with CASL.
Express consent vs implied consent
CASL distinguishes two forms of consent. Express consent: the recipient ticked a dedicated checkbox (not pre-ticked) to receive your communications. This consent doesn't expire. Implied consent: there's an existing business relationship (purchase in the last 24 months) or a recent personal/family relationship — you can send for 2 years after the triggering event. 4invoices distinguishes these two types and tracks the origin of consent (web form, signed contract, purchase, event) with immutable timestamping.
Clear sender identification
Every commercial message must unambiguously identify the sender: full company name (legal name), valid physical mailing address, phone number or email of a representative. 4invoices automatically verifies the presence of these elements in every marketing email template and blocks sending if information is missing. For invoices, this information is automatically included from your business profile.
Unsubscribe mechanism within 10 business days
Every commercial message must contain a free and easy-to-use unsubscribe mechanism. A recipient who unsubscribes must be removed from sends within 10 business days — a period during which a final communication confirming the unsubscribe is allowed. 4invoices processes unsubscribes automatically via unique link with cryptographic signature, and blocks subsequent sends to the same address within minutes of the click.
What's exempt from CASL
CASL provides several important exceptions for legitimate business communication. Invoices, receipts, warranties, payment reminders and communications relating to an ongoing transaction are not commercial electronic messages within the meaning of CASL — they don't require consent. You can send an invoice without explicit opt-in because the existing contractual relationship authorises the communication. Similarly, payment reminders and default notices aren't marketing.
On the other hand, the moment a message contains a commercial call to action — promotion, flash sale, seasonal offer, newsletter, product demo, link to a payment page — it falls within CASL's scope. The boundary is sometimes fine: is a thank-you email after a purchase with a link to other products an invoice or marketing? Cautious rule: if more than 20% of content is promotional, treat it as a commercial message under CASL.
For registered charities and political parties, partial exceptions apply. For business-to-business communications between officially registered representatives of businesses, implied consent can be broader. For surveys, academic research and non-commercial communications, CASL doesn't apply. But when in doubt, the prudent standard is to obtain express consent and track its origin — which is what 4invoices does by default for all marketing communications.
Frequently asked
I bought an email list from a reputable company. Can I use it?
No, not without prior individual express consent. CASL doesn't recognise the legality of purchased lists, even if the vendor guarantees compliance. Each recipient must have given direct consent to your business or have a pre-existing business relationship with you. Using a purchased list is one of the most frequently sanctioned cases by the CRTC, with 6-figure fines.
My website uses a pre-checked newsletter checkbox. Compliant?
No. CASL requires an affirmative action to give consent — the box must be empty by default and the recipient must actively tick it. A pre-checked box isn't valid express consent. 4invoices provides CASL-compliant signup form templates with unchecked-by-default boxes.
A customer unsubscribes. Can I still send them their invoices?
Yes. Marketing unsubscribe doesn't affect transactional communications (invoices, receipts, payment reminders, account updates). You keep sending invoices via email even if the customer unsubscribed from your newsletter. 4invoices handles these two communication tracks independently — marketing opt-out doesn't stop invoicing.
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