What happens to unused RDTOH if I wind up my Ontario corporation?

If a corporation is wound up with unused RDTOH still sitting in the account, that balance is at real risk of being lost, since the refund mechanism is tied to actually paying a taxable dividend, and a corporation that ceases to exist without paying a sufficient dividend beforehand may never trigger the refund it would otherwise have been entitled to. This is a genuinely common, avoidable planning gap when a corporation is dissolved without thinking through its RDTOH position first.

The practical fix is to plan the wind-up so that a dividend, including amounts distributed to shareholders as part of the winding-up process itself, which can be treated as a deemed dividend for tax purposes, is paid before or as part of dissolution, specifically sized to draw down the available RDTOH balance rather than leaving it stranded. Doing this properly requires coordinating the timing and amount of final distributions with the corporation's actual RDTOH balance, not just distributing whatever assets remain without regard to the tax mechanics involved.

Because winding up a corporation is usually a one-time event with no opportunity to go back and fix a missed refund afterward, reviewing the RDTOH balance and building a deliberate final-dividend strategy into the wind-up plan, well before the corporation is actually dissolved, is essential.