What happens if I never respond to a procedural fairness letter at all?

If no response is given at all, IRCC will generally proceed to decide the application based on the information already on file, including whatever concern the letter raised. Since the specific concern was, by definition, never addressed, this usually leads directly to a refusal grounded in that unaddressed issue, because the officer has no further information to weigh against it.

There is no automatic entitlement to a further extension once the deadline has already passed without any response, though requesting more time before the deadline lapses, with a genuine and specific reason, is always a reasonable step to take rather than simply staying silent. Once the deadline is missed entirely, the decision-maker has little practical reason to wait further, since the letter's entire purpose was to give a defined opportunity to respond that has now passed.

Anyone who receives a procedural fairness letter and cannot fully address it in time should still submit something before the deadline — even a partial response or a request for more time — rather than allowing the deadline to pass without any communication at all, since silence generally produces the worst realistic outcome.