Suppose a US-resident taxpayer provides services in Canada for 130 days between 1 October to 28 February, does not anticipate providing further services in Canada, and obtains regulation 105 waivers for services provided in that period. Nevertheless, the taxpayer returns to Canada to provide services for 60 days between 1 July to 31 August the same year. This would trigger Art. V(9)(a) of the Canada-US Convention retroactively to impute a permanent establishment. The taxpayer would thus be late in filing a T1 in respect of income from Canada for 1 October-31 December.
CRA stated that it "may" apply relief provisions on the penalties and accumulated interest for 1 October-31 December - "Taxpayers will have to advise the CRA of their circumstances, and the CRA will review each request on the basis of the information provided."
CRA does not expect retroactive remittances for the period where the waivers were valid, but withholdings must commence starting 1 July. The taxpayer is obligated to file T1 forms and pay the resulting Canadian income tax liability from the 1 October-28 February period.