Liquidator notification requirement: Commissioner assesses and notifies amount sufficient to secure GST liabilities in liquidation. The liquidator must notify the Commissioner of his appointment within thirty days, and the Commissioner shall inquire and notify the liquidator of the amount deemed sufficient to secure any tax, interest or penalty then due or likely to become payable. For private company windings up, where the company's determined GST liabilities cannot be recovered, every person who was a director during the relevant period is jointly and severally liable unless he proves to the Commissioner that non-recovery was not due to his gross neglect, misfeasance or breach of duty.