Subsection 168(1) states that GST/HST tax is generally payable on the earlier of when the consideration for the supply is paid and when it becomes due, the latter of which generally falls on the invoice date. However, in CFI Funding Trust v. The Queen, the Tax Court of Canada held that an invoice issued by the supplier is not necessary to claim an input tax credit and to satisfy requirements of the Excise Tax Act (Canada) and the Input Tax Credit Information (GST/HST) Regulations.