Streamlined Accounting (GST/HST) Regulations — 21.3
21.3 (1) If an election by a registrant to determine the net tax of the registrant in accordance with this Part is in effect during a reporting period of the registrant, the net tax of the registrant for the reporting period is, subject to this Part, the positive or negative amount of net tax for the reporting period determined in accordance with (a) if the registrant has filed an election to determine the net tax of the registrant in accordance with Part IV that is in effect during the reporting period, Part IV; (b) if the registrant has filed an election to determine the net tax of the registrant in accordance with Part V that is in effect during the reporting period, Part V; and (c) in any other case, subsection 225(1) of the Act. (2) If personal property or a service is supplied in Canada to a registrant by another person, or tangible personal property is supplied outside Canada to a registrant by another person and imported by the registrant, and the registrant is entitled to claim an input tax credit in respect of the property or service for any reporting period of the registrant, for the purposes of determining (a) an input tax credit of the registrant in respect of the property or service for a particular reporting period of the registrant, and (b) an amount that is required by subsection 235(1) of the Act to be added in determining the net tax of the registrant for any reporting period, for the purposes of this Part, the amount of tax under Division II or III, as the case may be, that became payable, or was paid without having become payable, by the registrant during the particular reporting period in respect of the supply or importation of the property or service is deemed to be equal to the amount determined by the formula A × B where A is the amount determined by the formula C / D where C is (i) if tax under subsection 165(2) or section 212.1 of the Act was payable in respect of the supply or importation, the total of the rate set out in subsection 165(1) of the Act and the tax rate of the participating province that applied in respect of the supply or importation, and (ii) in any other case, the rate set out in subsection 165(1) of the Act, and D is the total of 100% and the percentage determined for C, and B is the total of all amounts each of which is (a) the consideration that became due, or was paid without having become due, by the registrant during the period in respect of the supply of the property or service to the registrant, (b) the tax under Division II or III that became payable, or was paid without having become payable, by the registrant during the period in respect of the supply or importation of the property or service, (c) in the case of tangible personal property that was imported by the registrant, the amount of a tax or duty imposed in respect of the property under the Act (other than Part IX), the Customs Act , the Special Import Measures Act or any other law relating to customs, that became due, or was paid without having become due, by the registrant during the period, (d) the amount of a tax, duty or fee prescribed by paragraph 3(b) or (c) of the Taxes, Duties and Fees (GST/HST) Regulations that became due, or was paid without having become due, by the registrant during the period in respect of the property or service, other than tax imposed under an Act of a legislature of a province to the extent that the tax is recoverable by the registrant under that Act, (e) a reasonable gratuity paid by the registrant during the period in connection with the supply, or (f) interest, a penalty or other amount paid by the registrant during the period if the amount was charged to the registrant by the supplier because an amount of consideration, or an amount of a tax, duty or fee referred to in paragraph (c) or (d), that was payable in respect of the supply or importation was overdue. (3) Subsection (2) does not apply to a passenger vehicle or aircraft acquired or imported by a registrant who is an indiv