I know here in my area (Saskatchewan, Canada)
That's not what the criminal code says. My father was a cop in SK for a time while teaching at Depot there. If you are one of the people involved in the conversation, you aren't obligated to tell anyone. Only if you record other parties who aren't aware of being recorded, ie, you plant a bug or a phone or something, and aren't a part of the conversation, does it become illegal wiretapping, recording, and interceptions according to the law.. Example is recording your wife's phone calls to see if she is having an affair - that is illegal in SK and the rest of Canada. You recording conversations between you and her about your upcoming divorce, you aren't obligated to tell her you're recording. You may have to advise others in your line of work due to company policy or something, but legally speaking, if you say one word in that conversation, or are even just present for it, you are under no legal obligation to do so in Canada.
This has been challenged before in Canada, but is still law. Here is an example of one such challenge back in 1995 that failed to change to law.
In La Compagnie D’Assurance Standard Life v. Renald Rouleau, [1995] R.J.Q. 1407 at para. 19 (S.C.) the Quebec Superior Court held that an employer surreptitiously recording telephone conversations with an ex-employee was not a violation of s. 184 of the Criminal Code.
This is why I said "if you're obligated" in my original post about recording, it varies greatly state by state in the USA, in Canada it is federal law and the criminal code that covers this, even though there have been challenges brought in provincial court, but that is usually just a route to federal supreme court, and like I said, has always failed to change things.