When is GST/HST due in Canada — and how do you keep the money aside?

GST/HST is generally due on a rhythm set by your business's assigned filing period — monthly, quarterly, or annual — with the payment deadline following the end of each period. The exact dates for your business depend on that period and your fiscal year, so confirm them against your CRA account or your accountant's calendar. What catches owners off guard is rarely the date itself. It is that the money being remitted was collected gradually, sat in the operating account looking like cash, and got spent.

Why the remittance feels like a surprise bill

When a customer pays an invoice that includes GST/HST, the full amount lands in your account. But the tax portion was never your revenue — you collected it on behalf of the government, and you will remit it (net of the input tax credits on your own taxed purchases). The operating account does not label the difference. A balance built partly from collected tax reads as spendable money, and in a tight month it gets spent like it.

Then the filing period ends, the return is prepared, and an amount the business "had" months ago is due on a fixed date — often in the same weeks as payroll and rent. The remittance did not change. The money's availability did.

The set-aside habit

The businesses that find remittance week boring share one habit: they move the tax portion out of spending reach as it arrives, not when it is due.

• Estimate as you invoice. For each payment received, set aside roughly the GST/HST portion collected, minus what you expect to claim back on purchases in the same period. It does not need to be perfect — a close, consistent estimate beats a precise one made in a panic.
• Use a separate account or a clearly tracked reserve. A second account makes the separation physical. If everything stays in one account, track the reserve as a number you subtract before making any spending decision — the same way you would treat payroll money.
• Reconcile at period end, not at deadline. When the return is prepared, compare the reserve to the actual amount owing and adjust the difference immediately, while there is still time before the payment date.
• Place the remittance on your cash timeline. Whatever the amount turns out to be, it is a dated, fixed outflow like rent. It belongs in the same forward view as payroll and supplier payments — especially for quarterly and annual filers, where the amount is larger and the collision risk is higher.

Quarterly and annual filers: the bigger trap

Monthly filers feel the remittance as a routine. Quarterly filers accumulate three months of collected tax; annual filers can accumulate far more, and annual filers may also have quarterly instalments to manage. The longer the period, the more the collected tax blends into working capital — funding stock, covering a slow month — and the larger the single payment when it comes due. If your business files quarterly or annually, the set-aside habit is not optional bookkeeping hygiene; it is the difference between a planned payment and a crisis.

What this is not

Filing periods, deadlines, instalment requirements, and input tax credits all have specific rules that depend on your business's situation. This article is about cash management, not tax advice — confirm your obligations and dates with the CRA or your accountant, and let their calendar set the dates on your timeline.

One timeline for every fixed payment

Monimate Business is being built to place a business's fixed commitments — payroll, rent, supplier payments, and tax remittances — on one forward timeline alongside expected customer payments, so the weeks where they collide are visible while there is still time to prepare. It is currently in development, and early access is open to Canadian small businesses.

Request early access to help shape it.