HST Filing Deadlines in Ontario: 2026 Complete Guide

HST/GST Filing Deadlines in Ontario (2026)

If you operate a business in Ontario and are registered for HST/GST, you must file returns with the Canada Revenue Agency (CRA) on a regular schedule. Missing these deadlines results in penalties and interest that compound quickly.

This guide covers everything Ontario business owners need to know about HST filing deadlines in 2026 — including Q1 2026 due dates that are coming up fast.

Who needs to file HST/GST returns?

You must register for HST/GST if your total worldwide taxable revenues (including those of any associated businesses) exceed $30,000 in any single calendar quarter or over four consecutive calendar quarters.

You can also register voluntarily before reaching this threshold, which allows you to claim Input Tax Credits (ITCs) on business purchases.

HST Filing Frequencies

CRA assigns your filing frequency based on your annual taxable revenues:

2026 HST Due Dates — Quarterly Filers

For businesses filing quarterly, returns and payments are due:

• ●Q4 2025 (Oct–Dec): February 28, 2026 ⚠️ Already passed
• ●Q1 2026 (Jan–Mar): April 30, 2026 — Coming up
• ●Q2 2026 (Apr–Jun): July 31, 2026
• ●Q3 2026 (Jul–Sep): October 31, 2026
• ●Q4 2026 (Oct–Dec): February 28, 2027

2026 HST Due Dates — Annual Filers

If your fiscal year ends December 31, 2025, your annual HST return and payment are due March 31, 2026. This is one of the most commonly missed deadlines for small businesses — it coincides with year-end accounting and personal tax season.

CRA Late-Filing Penalties

If you file your HST return late, CRA will assess a penalty of:

• ●1% of the unpaid amount
• ●Plus 0.25% of the unpaid amount for each complete month the return is outstanding (maximum 12 months)

Example: If you owe $5,000 in HST and file 3 months late, your penalty would be $50 (1%) + $37.50 (0.25% × 3 months) = $87.50 — plus daily interest at ~8%.

Interest on unpaid amounts accrues from the due date at CRA's prescribed rate (currently ~8% for 2026).

What if I Can't Pay?

If you can file but can't pay the full amount, file anyway. Late-filing penalties are separate from late-payment interest. Filing on time while owing a balance stops the penalty clock — you'll only owe interest on the unpaid amount, not the additional 0.25% monthly penalty.

CRA also offers payment arrangements for businesses that cannot pay in full.

Tips to Never Miss an HST Deadline

1. Set calendar reminders 2 weeks before each deadline 2. Automate with cloud software — QuickBooks and Xero track HST automatically throughout the year 3. Work with a professional bookkeeper who files on your behalf before every deadline 4. Don't wait for the deadline — if your books are current, file early 5. Check your CRA My Business Account — your filing frequency and any outstanding returns are listed there

At Outsource Bookkeeping, we prepare and file your HST returns as part of our flat-rate monthly service. You'll never receive a CRA penalty for a late filing while working with us — guaranteed.