GST Filing Deadlines Every Calgary Business Should Know

If your Calgary business earns more than $30,000 in revenue over four consecutive quarters, you're required to register for and collect GST (Goods and Services Tax) at 5%. But collecting it is only half the battle — you also need to file and remit on time. Here's what you need to know.

Filing Frequencies

CRA assigns your filing frequency based on your annual revenue:

• Annual filing — revenue under $1.5 million. Your return is due three months after your fiscal year-end.
• Quarterly filing — revenue between $1.5 million and $6 million. Returns are due one month after each quarter ends.
• Monthly filing — revenue over $6 million. Returns are due one month after each reporting period.

You can voluntarily elect a more frequent filing period if it suits your cash flow — many businesses prefer quarterly filing even if they qualify for annual.

Key Deadlines for 2026

For businesses on a calendar fiscal year with quarterly filing:

• Q1 (Jan–Mar) — due April 30, 2026
• Q2 (Apr–Jun) — due July 31, 2026
• Q3 (Jul–Sep) — due October 31, 2026
• Q4 (Oct–Dec) — due January 31, 2027

Penalties for Late Filing

CRA charges a penalty of 1% of the balance owing plus 0.25% for each month the return is late, up to 12 months. Interest also accrues on the unpaid balance at the prescribed rate, which is adjusted quarterly.

Input Tax Credits (ITCs)

Don't forget — you can claim back the GST you paid on business expenses through Input Tax Credits. Proper bookkeeping ensures you capture every eligible ITC, which reduces your net GST remittance. Many Calgary businesses leave money on the table by not claiming all their ITCs.

Let Castle Keep You on Track

Our monthly bookkeeping plans include GST filing so you never miss a deadline. We calculate your net GST, prepare the return, and file it with CRA on your behalf. One less thing to worry about.