One-quarter versus four-quarter GST/HST threshold timing

Calendar quarters are fixed

A calendar quarter is January through March, April through June, July through September, or October through December. The tests do not use any freely selected 90-day period or a simple trailing 12-month total by date.

CRA's June 2026 small-supplier memorandum assigns consideration to a quarter when it becomes due or is paid without first becoming due. An unpaid invoice can count after it becomes due, and a prepayment can count before the work is completed.

Exactly C$30,000 does not exceed the threshold. The test changes when the applicable countable total goes over C$30,000.

Test one: a single quarter exceeds C$30,000

CRA says the business is no longer a small supplier immediately before the consideration for the supply that makes the calendar-quarter total exceed C$30,000 becomes due or is paid without becoming due. The effective registration date is no later than that day. The entire crossing supply—not only the amount above C$30,000—is subject to its applicable rate; a properly zero-rated crossing supply remains taxable at 0%.

The instruction to register within 29 days does not create 29 tax-free days. The charging obligation can begin on the effective date.

Test two: completed quarters exceed C$30,000

When the previous four or fewer consecutive calendar quarters exceed C$30,000 but no single quarter does, CRA says small-supplier status ends at the end of the month following the crossing quarter.

The effective registration date is no later than the first taxable supply made in Canada after small-supplier status ends. Track the quarter-end, the end of the following month, and that first later in-Canada taxable supply as three separate dates.

Do not combine the timelines

The current incomplete quarter is useful for planning, but the completed-quarter test is determined at quarter-end. At the same time, the single-quarter test can change the answer before quarter-end because the crossing supply itself matters.

A reliable tracker therefore needs a live single-quarter total and a separate history of completed calendar quarters. One generic annual-revenue progress bar is not enough.

Special cases need different rules

The ordinary C$30,000 tests do not cover every person. Taxi and commercial ride-sharing operators generally must register from the start of that activity. Charities, public institutions, other public service bodies, non-residents, and Québec QST situations can follow additional or different rules.