GST/HST Registration Threshold Calculator
See whether the CRA's $30,000 small-supplier threshold has been crossed across rolling 4-quarter windows, and estimate whether voluntary registration would pay off given your customer mix and ITC recovery.
Last 5 Quarters of Taxable Supplies
Enter pre-tax revenue for each of the past 4 quarters plus the current quarter-to-date. Include all taxable supplies (zero-rated count, but exempt do not).
Still a Small Supplier
You remain a small supplier — neither any single quarter nor any rolling 4-quarter window exceeded $30,000. Registration is voluntary.
| Quarter | Revenue | Rolling 4Q Total | vs $30K |
|---|---|---|---|
| Q-4 | $4,000 | — | — |
| Q-3 | $5,000 | — | — |
| Q-2 | $6,000 | — | — |
| Q-1 | $7,000 | $22,000 | Under |
| Q0 | $8,000 | $26,000 | Under |
Voluntary Registration ROI — B2B
ITCs Recovered
+$2,000
Admin Cost
-$1,000
Net Annual
+$1,000
B2B customers recover the GST/HST you charge via their own Input Tax Credits, so charging tax adds no price pressure. You collect $2,000 in ITCs on your inputs and pay $1,000 in admin overhead.
Quick Method Preview (if registered)
With annual revenue of $26,000 ($29,380 tax-included), you're eligible for the Quick Method (under the $400,000 cap).
Regular Method Remittance
$3,380
Quick Method Remittance
$2,292
Quick Method Savings
$1,088
Comparison vs no-ITC baseline. Quick Method gives up the right to claim ITCs on most inputs, so real savings depend on how much GST you pay on business expenses.
How CRA's $30,000 test works: Aggregate your taxable supplies (and those of associated persons) over any four consecutive calendar quarters. If the rolling total exceeds $30,000 at any point, you cease to be a "small supplier" effective the end of the month following that quarter — and must register within 30 days. A single calendar quarter exceeding $30,000 is a faster trigger: you cease being a small supplier immediately in that quarter, and GST/HST applies to that quarter's revenue too.
Small Supplier Rules — What Counts and What Doesn't
Include in your $30,000 test: All taxable worldwide supplies (sales of taxable goods and services, including zero-rated supplies). Add the taxable supplies of any associated persons under ETA s.148(2).
Don't include: Exempt supplies (residential rent, most financial services, basic groceries), supplies made outside Canada that aren't connected to a Canadian permanent establishment, and the sale of capital property.
When threshold is crossed:
- Rolling 4-quarter breach: You cease to be a small supplier at the end of the month following that quarter. Register and start charging GST/HST by that date.
- Single-quarter spike: You cease to be a small supplier immediately in that quarter. GST/HST applies to the supply that pushed you over.
Voluntary registration: Small suppliers can register voluntarily to claim Input Tax Credits on business inputs. The trade-off is the GST/HST you collect from customers (a real cost if customers can't recover it) plus admin overhead. B2B businesses generally benefit; B2C businesses need ITC recovery that exceeds the price elasticity hit.
Sources
Last updated May 2026. Reflects 2026 GST/HST rates and the $30,000 small-supplier threshold.
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