Not necessarily. According to the CRTC, the simple inclusion of a logo, a hyperlink or contact information in an email signature does not necessarily make an email a commercial electronic message (CEM) under Canada's anti-spam law (CASL), but a tagline that promotes a product or service, or encourages the recipient to buy one, would. The line is drawn by the content and purpose of the message, not by the mere presence of a signature.
This is not legal advice. This page summarizes what the CRTC and the text of the law say, with links to each source. Whether a given message is a CEM depends on its content and purpose; for your organization, ask a lawyer.
Does a logo or a link in my signature make every email a CASL message?
The CRTC answers this in its frequently asked questions on CASL. On email signatures, it says that the simple inclusion of a logo, a hyperlink or contact information in an email signature does not necessarily make an email a CEM. Conversely, a tagline in a message promoting a product or a service, or encouraging the recipient to purchase a product or service, would constitute the message as a CEM.
To decide whether one of the purposes of a message is to promote a commercial activity, the CRTC tells you to look at the content of the message, the hyperlinks in it to website content or a database, and the contact information. It adds that these parts of the message are not determinative: none of them settles the question alone.
If a message is a CEM, the same FAQ lists obligations that apply to it. Two of them bear directly on a signature:
- An unsubscribe mechanism. A CEM must include one; a clear and prominent hyperlink in the email that lets the recipient unsubscribe with a simple click is acceptable.
- Sender identification. Where it is not practicable to include the identification information in the body of the message, a hyperlink to a webpage containing it is acceptable.
Do others read the rule more strictly?
Yes. Conestoga College, in its page on Canada's anti-spam legislation, writes that the CEM rules apply to messages sent by any employee or representative of an organization, and that if an email signature includes a logo, hyperlink or tagline that promotes a commercial activity, every email you send may be considered a CEM.
That is an institution's own, more cautious reading, for its own staff. It is not the regulator's position and it is not a rule of the law. The two statements do not conflict as much as they seem: both turn on whether the signature promotes a commercial activity. The difference is how readily each treats a logo or a link as promotion, and a signature that carries a promotional line is where both statements call for care.
When did CASL come into force?
On Justice Laws, the Act (S.C. 2010, c. 23) carries a note on coming into force: sections 1 to 7 and 9 to 46, among others, came into force on July 1, 2014, and section 8 (the installation of computer programs) on January 15, 2015, see SI/2013-127. The rules on commercial electronic messages, section 6, are therefore in force since July 1, 2014. The page consulted was current to October 19, 2026.
What should I do with my organization's signatures?
Without giving legal advice, three habits follow from the sources above:
- Separate identity from promotion. Keep the permanent signature to identification and contact information. The CRTC treats those elements as not determinative on their own.
- Treat a promotional line as a decision, not a decoration. A tagline that promotes a product or encourages a purchase is what the CRTC names as making a message a CEM. If you add one, have your advisor decide how the unsubscribe and identification obligations apply.
- Make a promotional banner temporary and targeted. In ATOM, a campaign banner has a start date, an optional end date and a time zone, and it is aimed at groups, people or shared mailboxes, with exclusions; the permanent signature stays unchanged. The guide on a seasonal banner for all employees shows the steps.
To go further on the rules around signatures, see email signatures and Law 25 (personal information, a separate matter from CASL), email signature templates and signatures by Microsoft 365 group. For the marketing side, see the signature as a marketing channel, and to compare tools, email signature software in Canada.
ATOM Signatures inserts the signature and the campaign banner that your administrator configures; it does not decide whether a message is a CEM. That assessment remains with your organization and its legal advisor.
Frequently asked questions
Does a logo in my email signature make every email a commercial message?
Not necessarily. According to the CRTC, the simple inclusion of a logo, a hyperlink or contact information in an email signature does not necessarily make an email a commercial electronic message. A tagline that promotes a product or service, or encourages the recipient to buy one, would. This is not legal advice.
Is a link to my website in my signature a commercial message?
Not by itself, according to the CRTC, which names hyperlinks among the parts of a message that are not determinative on their own. The content, the links and the contact information are looked at together to decide whether one purpose of the message is to promote a commercial activity.
Why does Conestoga College say every email may be a commercial message?
Conestoga College writes that if an email signature includes a logo, hyperlink or tagline that promotes a commercial activity, every email sent may be considered a commercial electronic message. That is the college's own cautious reading for its staff, not the CRTC's position; the CRTC's wording is that a logo, link or contact information does not necessarily make an email a CEM.
When did Canada's anti-spam law come into force?
According to the coming-into-force note on Justice Laws, sections 1 to 7 and 9 to 46 of the Act came into force on July 1, 2014, and section 8, on the installation of computer programs, on January 15, 2015. The rules on commercial electronic messages are in section 6.
What must a commercial message include, according to the CRTC?
The CRTC's FAQ says a commercial electronic message must include an unsubscribe mechanism; a clear and prominent hyperlink that lets the recipient unsubscribe with a simple click is acceptable. It also says that where identification information cannot practicably be put in the body of the message, a hyperlink to a webpage containing it is acceptable.
Is this page legal advice?
No. This is not legal advice. The page summarizes what the CRTC, Conestoga College and the text of the law say, with a link to each. For your organization's situation, ask a lawyer.
Keep your signatures identical across the organization. ATOM Signatures costs CA$1 per user per month, plus taxes, with a 14-day free trial.
Sources
- CRTC — Frequently asked questions about Canada's anti-spam legislation (CASL): crtc.gc.ca
- Conestoga College — Canada's Anti-Spam Legislation: conestogac.on.ca
- Justice Laws — S.C. 2010, c. 23 (E-1.6), coming-into-force note, current to October 19, 2026: laws-lois.justice.gc.ca
Sources consulted on November 2, 2026. This is not legal advice.