Can CRA collect a corporation's tax debt from its directors personally?

Yes, in specific circumstances. Directors of a corporation can become personally liable for the corporation's unremitted source deductions and unremitted GST/HST if the corporation fails to remit them, a rule commonly called director's liability. This means CRA can pursue directors personally once the corporation itself has failed to pay these particular categories of debt, which the law treats as money the corporation was holding in trust rather than its own funds to begin with.

This doesn't mean liability is automatic or unavoidable in every situation, though. Director's liability comes with its own defences and limitation periods, and whether a specific director is actually liable depends on the facts of their involvement and the circumstances around the corporation's failure to remit - this is a genuinely fact-specific area, not a blanket rule that every director of every corporation with unpaid remittances is automatically on the hook. If you're a director of a corporation that has fallen behind on source deductions or GST/HST remittances, understanding both the real risk this creates and the potential defences available to you is important, since assuming either that you're automatically safe or automatically liable would both be mistakes.