How much time does someone have to respond to a demand letter in Ontario?

There is no fixed legal deadline set by Ontario statute for responding to a demand letter. The sender sets the deadline, and it is typically somewhere between 10 and 30 days depending on the nature and complexity of the claim.

What is reasonable depends on the circumstances. A demand for a small, clear-cut debt might give 14 days; a complex commercial dispute might allow 30 days so the other side can consult legal counsel. Courts expect demands to include a reasonable response window — a deadline of 24 or 48 hours would rarely be considered fair unless there is an emergency situation such as ongoing harm.

Ignoring a demand letter is almost always a mistake. Silence does not make the claim disappear and can be used as evidence of bad faith or willful disregard. If you receive a demand letter, you should respond — even if just to acknowledge receipt or state that you are seeking legal advice — within the stated period. If you sent the letter and received no response, you may then consider filing in the appropriate Ontario court or tribunal, such as Small Claims Court for amounts up to the applicable limit.