How often do I have to file GST/HST?

How this is calculated

Three bands decide the period the CRA assigns you. At or below $1,500,000 in annual taxable supplies you get an annual period. Above that up to $6,000,000, quarterly. Above $6,000,000, monthly: and there is no way down from that one.

In the lower two bands the assigned period is a floor, not a ceiling: you can elect to file more frequently. That election is the useful part of this page, because it is a genuine cash-flow lever. If the tax you pay on purchases regularly exceeds what you collect: common for a business investing heavily, or one making mostly zero-rated supplies like exports: every return is a refund. Filing monthly rather than annually gets that money back months earlier.

The trade is administrative: twelve returns a year instead of one, each of which has to reconcile. That is a fair trade when the refund is material and a poor one when your net tax is small.

Charities are assigned an annual period regardless of revenue, and listed financial institutions are treated separately again.

Whichever period you land on, the reconciliation is the same job: the tax you collected and the tax you paid have to agree with what the ledger says before the return goes in. Comma keeps both sides in their own accounts as you invoice and enter bills, so the return is a number you read rather than one you rebuild.