How to File Your GST/HST Return: Step by Step

Filing your GST/HST return doesn't have to be stressful. If you've been tracking your sales and expenses throughout the reporting period, the actual filing takes about 15 minutes. This guide walks through every step, from choosing your filing method to submitting and paying.

Before You Start

Make sure you have:

• Your Business Number and GST/HST program account number (format: 123456789RT0001)
• Total revenue for the reporting period
• Total GST/HST you collected (or should have collected) on sales
• Total GST/HST you paid on eligible business purchases (your Input Tax Credits)
• Access to CRA My Business Account or compatible NETFILE software

The Filing Process

Filing Methods

You have three ways to file:

For most one-person corporations, filing through My Business Account is the simplest option. You fill in the numbers directly on the CRA website.

Line-by-Line Breakdown

The GST/HST return (Form GST34) has several lines, but only a handful matter for a typical small corporation. Here's what each key line means.

Revenue Lines

Line 101: Total revenue (before GST/HST) This is your total sales and revenue for the reporting period, before adding any GST/HST. Include all taxable, zero-rated, and exempt supplies.

If your total annual revenue was $150,000 and you file quarterly, enter the revenue for that specific quarter.

Line 105: Total GST/HST collected or collectible This is the GST/HST you charged (or should have charged) on your taxable supplies. If you're in a GST-only province and made $50,000 in taxable sales:

For HST provinces, the rate varies. Ontario charges 13%, New Brunswick and Newfoundland charge 15%, and Nova Scotia charges 14%.

Input Tax Credit Lines

Line 106: Total ITCs (GST/HST paid on business purchases) This is where you claim back the GST/HST you paid on eligible business expenses. Common ITC-eligible expenses include:

• Office supplies and equipment
• Software subscriptions
• Professional services (legal, accounting)
• Business travel and meals (50% for meals)
• Rent for office space
• Internet and phone (business portion)

Line 108: Total ITCs This is the total from Line 106, plus any adjustments. For most simple returns, Line 108 equals Line 106.

The Bottom Line

Line 109: Net tax This is the key number. It's calculated automatically:

If Line 109 is positive, you owe CRA that amount. If it's negative, you're getting a refund (this is common for businesses that have more expenses than revenue in a period, or that make mostly zero-rated supplies).

Other Lines

Line 110: Installments paid If you made quarterly installments, enter the total here. This reduces your balance owing.

Line 111: Rebates Most small corporations leave this blank unless you're claiming a specific GST/HST rebate (e.g., new housing rebate for builders).

Line 112: Total other credits Enter any other credits, such as amounts transferred from other returns.

Line 113: Balance (net tax minus credits and installments) This is your final amount owing or refund. The system calculates it for you.

Filing Deadlines

Your filing deadline depends on your reporting period:

For example, if your fiscal year ends December 31 and you file annually, your GST/HST return and payment are due by March 31.

Step-by-Step: Filing Through My Business Account

1. Log in to your CRA My Business Account
2. Click "File a return" in the left menu
3. Select your GST/HST program account
4. Choose the reporting period you're filing for
5. Enter Line 101 (total revenue)
6. Enter Line 105 (total GST/HST collected)
7. Enter Line 108 (total ITCs)
8. Review Line 109 (net tax, auto-calculated)
9. Confirm and submit

After submission, you'll see a confirmation number. Save it. Your return will appear in your filing history within a few business days.

Common Mistakes to Avoid

Claiming ITCs on personal expenses. If you use your phone 50% for business, you can only claim 50% of the GST on the phone bill. CRA audits ITCs regularly.

Missing the small supplier threshold. If you voluntarily registered for GST/HST (revenue under $30,000), you still must file returns for every reporting period, even if revenue is zero. File a nil return.

Forgetting to include HST on out-of-province sales. If you're in BC (GST only) but sell taxable digital products to a customer in Ontario, the place of supply rules may require you to charge 13% HST. Get familiar with the place-of-supply rules or ask your accountant.

Not reconciling before filing. Don't just estimate. Reconcile your GST collected and ITCs against your actual bank transactions and invoices. Small errors compound over multiple filing periods.

How ledg Helps

ledg categorizes every transaction and automatically calculates your GST/HST collected and Input Tax Credits. When filing day arrives, your Line 105 and Line 108 numbers are ready to enter into CRA's portal.