In Canada, debt Validation is not legislated federally or in any Canadian provinces as it is in the U.S under Section 809b of the FDCPA.
However, in Common Law provinces (which mean all provinces except Quebec) the English Law doctrine of "estoppel by silence" applies and it is a similar concept because the Validation of Debt in the U.S works under the same principle except it was made in to law by congress using the logic of estoppel.
In British-Columbia, the Honourable Madam Justice Ross in Costco Wholesale Canada Inc. v. Cazalet, 2008 BCSC 952 applied this doctrine in a different case than a debt as quoted below.
"In, Spencer Bower, The Law Relating to Estoppel by Representation, 4th ed. by Piers Feltham, Daniel Hochberg & Tom Leech (London: LexisNexis UK, 2004; reprinted by Tottel Publishing, 2007) the authors state the following at para. I.2.2 regarding estoppel by representation:
Under the doctrine of estoppel by representation of fact: where one person (‘the representor’) has made a representation of fact to another person (‘the representee’) in words or by acts or conduct, or (being under a duty to the representee to speak or act) by silence or inaction, with the intention (actual or presumptive) and with the result of inducing the representee on the faith of such representation to alter his position to his detriment, the representor, in any litigation which may afterwards take place between him and the representee, is estopped, as against the representee, from making, or attempting to establish by evidence, any averment substantially at variance with his former representation, if the representee at the proper time, and in the proper manner, objects thereto."
That means that under the doctrine of estoppel by representation of fact: the Debtor (‘the representor’) makes a representation by words with a letter to validate the debt to a Creditor stating facts (facts stating that you do not owe the debt). That letter is the representation of fact to the creditor (‘the representee’), since the creditor has hired an agency to harass you by phone or engaged in other collections activities such as reporting the debt in credit bureaus, the Creditor is under a duty to the Debtor to speak or act. If the Creditor fails to respond within a reasonable time frame (30 days), his silence or inaction, renders the creditor estopped (stopped), as against the debtor, from making, or attempting to establish by evidence that you owe any debt. (Even if the Creditor is right and has evidence against you and you really owe the debt, the Doctrine of Estoppel is applicable in Common Law provinces in Canada and it bars the creditor to make that claim in court).