[ITA] Section 227.1 places certain limitations on the director’s liability. Two of these limitations are relevant for the purposes of these appeals. Paragraph 227.1(2)(a) provides that a director is not liable under subsection 227.1(1) unless “a certificate for the amount of the corporation’s liability referred to in that subsection [227.1(1)] has been registered in the Federal Court under section 223 and execution for that amount has been returned unsatisfied in whole or in part”.
 Subsection 323(1) of the GST Act imposes a similar director’s liability in respect of unremitted GST/HST. Subsection 323(1) of the GST Act provides that the directors of a corporation are jointly and severally liable to pay any amount of net tax that the corporation fails to remit. A director’s liability under subsection 323(1) includes any interest on, or penalties relating to, the net tax that is not remitted.
While this is a helpful decision, it's not clear that the conclusion goes as far as it should. If the Federal Court certificates did not equal the amounts assessed, it seems that the assessments were invalid. CRA would need to reassess. If the limitation period has passed (because the director had resigned more than two years earlier, for example) it may be too late to reassess.
See Maxwell v. The Queen 2015 TCC 74 (D'Arcy)