HST Filing Deadlines in Ontario: What Small Business Owners Need to Know

HST filing is one of those things that doesn't seem urgent until it is. Then you're scrambling to pull numbers together at 11 PM the night before the deadline, hoping you haven't missed anything. I've seen it happen too many times.

The Basic Rules

If your business earns more than $30,000 in revenue over four consecutive calendar quarters, you must register for an HST number and start collecting and remitting HST. In Ontario, that's 13% (5% federal GST + 8% provincial PST).

Once you're registered, you need to file returns on a schedule that depends on your annual revenue:

• Annual filers (under $1.5M in revenue). File once a year, due three months after your fiscal year-end.
• Quarterly filers ($1.5M to $6M). File four times a year, due one month after each quarter ends.
• Monthly filers (over $6M). File every month, due one month after each reporting period.

Key Dates for Annual Filers (Calendar Year-End)

If your fiscal year ends December 31 (which is most sole proprietorships and many small corporations), your HST return is due by March 31. But here's the catch. While the return is due March 31, any balance owing is due by April 30.

Wait, it gets more confusing. If you have a June 30 fiscal year-end, your return is due September 30 and your payment is due September 30 as well. The split deadline is only for December year-ends. Welcome to Canadian tax rules.

Quarterly Filing Deadlines

For quarterly filers with a December 31 fiscal year-end:

• Q1 (January-March): due April 30
• Q2 (April-June): due July 31
• Q3 (July-September): due October 31
• Q4 (October-December): due January 31

Both the return and the payment are due on these dates. No split deadlines for quarterly filers.

What Happens When You're Late

The CRA doesn't send gentle reminders. Here's what kicks in the moment you miss a deadline:

• Interest: Charged at the prescribed rate (currently around 7-8%) on any balance owing, starting the day after the due date.
• Late-filing penalty: 1% of the balance owing, plus 0.25% for each full month you're late, up to 12 months. On a $5,000 balance, that's $50 immediately plus $12.50 per month.
• Repeat offender penalty: If you've been late before, the penalty doubles.

I had a client come to me after missing two years of HST filings. The penalties and interest added up to over $3,200 on top of what they already owed. That's money that could have stayed in their pocket.

Quick vs. Regular Method

If your revenue is under $400,000, you may be eligible for the Quick Method of HST filing. Instead of tracking all the HST you paid on purchases (input tax credits), you remit a flat percentage of your revenue. For most service businesses in Ontario, that rate is 8.8%.

The Quick Method often saves money for service-based businesses that don't have a lot of HST-eligible expenses. It also makes bookkeeping simpler. Ask your bookkeeper or accountant if it's right for you.

How to Stay on Top of It

The simplest way to never miss a deadline: have your bookkeeper handle it. I file HST returns for all my clients as part of their monthly package. The numbers are reconciled throughout the month, so when filing day comes, it takes me about 15 minutes per client. No scrambling, no guessing, no penalties.

If you're currently handling HST yourself and it stresses you out, that's a sign. Reach out and let's get you set up properly before the next deadline.