How to Do a GST Return: Steps, Thresholds, and DIY Filing Guide

Few things feel as heavy as the first time a GST return is due—especially when you are not sure whether you even need to be filing one. For Canadian small businesses and self-employed people, the $30,000 small-supplier threshold is the line that separates optional registration from mandatory compliance, but the process of actually submitting a return can still feel shrouded in forms and numbers. Here are the concrete steps for filing with the Canada Revenue Agency (CRA), who must register, and whether you can confidently file the return yourself or should bring in a tax professional.

Small supplier threshold (Canada): $30,000 CAD over four consecutive quarters ·
Filing frequency: Quarterly, annual, or monthly depending on revenue ·
Late filing penalty: 1% of amount owing plus interest

Here is how the key filing thresholds and deadlines break down at a glance.

What are the steps for filing a GST return?

Filing a GST return follows three core phases: data collection, online submission, and payment. Here are the sequential steps.

1. Gathering sales data and invoices
   • Collect all sales records, including the GST/HST you charged customers.
   • Gather purchase invoices to identify eligible input tax credits (ITCs).
   • GST/HST registrants report tax charged or collected from customers and tax paid or payable to suppliers (CRA non-resident guide).
2. Filing the return online or via paper
   • Most registrants must file electronically; exceptions include charities and selected listed financial institutions (CRA reporting requirements).
   • Filing channels include CRA online services, GST/HST NETFILE, GST/HST TELEFILE, certified accounting software, or a participating Canadian financial institution (CRA filing options).
   • Paper filing exists but is slower and less common.
3. Making payment if required
   • Monthly and quarterly filers generally have one month after the end of the reporting period to file and pay (CRA deadlines).
   • Most annual filers have three months after fiscal year-end (CRA general registrant guide).
   • If your net tax is $3,000 or more as an annual filer, plan for quarterly instalments.

The implication: the “how to file” question is really two questions—what numbers go into the return, and which deadline applies to your business. Once you know your reporting period, the rest is data entry.

Can I file my GST return myself?

Advantages of DIY filing

• Many small business owners file their own GST returns using the CRA portal or certified accounting software.
• DIY filing is suitable for straightforward returns with clear sales totals and few capital purchases.
• Errors in self-filing can be corrected through adjustments—filing yourself is not a permanent commitment.

When to hire a professional

• Complex cases include multi-jurisdiction operations, partial exemptions, or significant capital acquisitions.
• Charities and selected listed financial institutions have different filing rules, which may warrant advice (CRA filing requirements).
• Cost-benefit analysis: a professional fee is usually far less than the interest and penalties on a missed deadline.

The pattern is clear: DIY filing works when your return is a clean subtraction of input tax credits from collected tax. The moment complexity compounds—multi-jurisdiction sales, partial exemptions, or large capital investments—the margin for error grows, and professional help becomes the economical choice.

Who needs to file a GST return?

Mandatory registration thresholds

• A business must register for GST/HST when taxable supplies exceed $30,000 in a single calendar quarter or over four consecutive calendar quarters (Canada Revenue Agency).
• The threshold is based on revenues before expenses from worldwide taxable supplies, aggregated with associated businesses (CRA definition).
• If you exceed the threshold in one quarter, you become a registrant on the supply that caused the breach (CRA policy).

Exempt supplies and organizations

• Charities have different rules and filing exemptions (CRA filing requirements).
• Certain businesses—taxi drivers and ride-hailing services—must register regardless of revenue under specific CRA rules.
• Non-profits may have partial rebates or different filing treatments.

Why this matters: the threshold is a revenue gate, but the real obligation begins the moment you cross it. Many owners underestimate the retroactive nature of catching up on filings and the interest that accrues from the trigger date.

Do I have to pay GST if I make less than $30,000?

Small supplier status

• If your taxable sales are below $30,000 in four consecutive quarters, you are generally a small supplier and not required to charge GST (CRA video transcript).
• Threshold applies to taxable sales, not total revenue—so exempt supplies don’t count toward the limit.
• Once you register voluntarily, you must charge and remit GST/HST even if revenue stays below $30,000 (CRA guidance).

Voluntary registration

• Voluntary registration is possible for businesses below the threshold (CRA video transcript).
• Voluntary registration allows you to claim input tax credits on purchases—a boon for businesses with large expenses.
• The trade-off: you must collect and remit GST/HST on your sales, which effectively raises your prices to customers.

The catch: staying a small supplier saves you the administrative burden but forfeits input tax credits on business purchases. For a startup with significant equipment costs, voluntary registration is often a net win—the credits you claim outweigh the tax you collect.

What this means: the $30,000 line isn’t a magical “free zone”—it’s a strategic decision point. Owners with capital-heavy operations should run the numbers; those with service-based income often prefer the simplicity of staying below it.

How do I file my GST/HST return with the CRA?

Accessing CRA My Business Account

• My Business Account is the CRA’s online portal for managing GST/HST, payroll, and corporate taxes.
• You can view your reporting period, file returns, and track payments through the portal.
• Registration requires your business number and a CRA login (either through the portal or a partner sign-in).

Using NETFILE or EFILE

• GST/HST NETFILE lets you file directly through the CRA website without software.
• GST/HST TELEFILE is a phone-based option for simple returns.
• Certified accounting software and participating financial institutions also support electronic filing (CRA filing methods).

Filing deadline and payment options

• Monthly and quarterly filers: one month after the reporting period ends (CRA deadlines).
• Annual filers: three months after fiscal year-end (CRA general guide).
• Sole proprietors with a December 31 year-end have a June 15 filing deadline but an April 30 payment deadline (CRA deadlines).
• Late filing incurs a penalty of 1% of the amount owing plus daily interest.

The discrepancy many owners miss: the payment deadline can arrive before the filing deadline for sole proprietors. You can file late, but the tax is due on the original date—interest runs from the payment deadline, not the filing deadline.

The trade-off is straightforward: electronic filing offers convenience and instant confirmation, while paper filing risks lost forms and processing delays. The CRA now pushes most registrants toward electronic channels, and the exceptions are narrow.

Confirmed vs. unclear

Confirmed facts

• The $30,000 small supplier threshold applies to taxable sales in Canada (CRA).
• GST returns must be filed within one month after the reporting period ends for monthly/quarterly filers (CRA deadlines).
• Voluntary registration is available for businesses below the threshold (CRA video).
• Net tax is calculated by subtracting input tax credits from collected GST/HST (CRA instructions).

What’s unclear

• Exact thresholds and rules vary by country; this guide addresses Canadian GST/HST only.
• Whether “tax back in Ireland” queries relate to GST, VAT, or income tax requires clarification.

Quotes from the field

“A business that exceeds the threshold in one calendar quarter becomes a registrant on the supply that caused it to exceed the threshold.”

Canada Revenue Agency (policy guidance, GST/HST registration)

“Once voluntarily registered, a business must charge and remit GST/HST and file returns even if revenue remains at or below $30,000.”

Canada Revenue Agency (guidance on filing obligations)

For Canadian small business owners, the choice is clear: file electronically, track your sales quarters carefully, and decide on voluntary registration with a calculator in hand. The DIY route—via My Business Account—is free, fast, and entirely within reach for most, but only if your records are organized enough to make the return a five-minute task rather than a weekend project.

Related reading: How to file a GST/HST return in Canada

Frequently asked questions