GST/QST Filing Basics in Québec (What You Need to Know)

Even when you have professionals managing your filings, it's good to understand the basics of GST and QST in Québec – especially since Quebec’s system has its quirks. Here are some key points (with French terms included for clarity):

Registration Requirements and Small Supplier Threshold

Most businesses in Canada must register for GST/QST once their sales reach a certain level. In Québec, if your total taxable worldwide sales (including those of associated businesses) exceed $30,000 in a single calendar quarter or over four consecutive quarters, you are no longer a "small supplier" and must register for both GST and QST. This is often referred to as the mandatory QST registration threshold (seuil d’inscription obligatoire à la TVQ).

·      Below $30,000: If you're under the threshold, registration is optional (many new or part-time businesses are in this category). You might choose to register voluntarily if you incur a lot of business expenses and want to claim ITCs/ITRs, but you will then have to charge TPS/TVQ on your sales.

·      Exceed $30,000: Once you cross $30k, registration is required by law. This applies even if you are a small business (petite entreprise); crossing the threshold means you must collect and remit GST/QST on your taxable sales going forward.

·      Special cases: Certain businesses must register for QST regardless of sales (for example, taxi drivers and ride-sharing drivers must register and charge GST/QST even if under $30k). Also, businesses outside Québec (out-of-province or international) that sell to Québec consumers may need to register under a specified QST system if they exceed $30,000 in Quebec sales – this was introduced in 2019 to capture online and out-of-province suppliers (obligations TPS/TVQ pour entreprises hors Québec).

If you’re unsure about your status, Mackisen can quickly determine if and when you need to register. We also handle the registration process for you, obtaining your GST/QST numbers from Revenu Québec so you can operate legally.

Reporting Periods and Deadlines (Dates limites TPS/TVQ)

When you’re registered for GST/QST, you’ll be assigned a reporting period frequency – usually monthly, quarterly, or annual – based on your sales volume. Larger businesses file more frequently, while smaller ones often file quarterly or annually. Revenu Québec (Revenu Québec) will confirm your filing frequency upon registration. Here’s a quick guide to deadlines:

·      Monthly or Quarterly Filers: Your GST/QST returns must be filed no later than one month after the end of each reporting period. For example, if you file quarterly and your quarter ends March 31, your return (and any payment) is due by April 30. A monthly filer would have the April return due by May 31, and so on.

·      Annual Filers: If you file once a year, the return is due no later than three months after the end of your fiscal year. So a business with a December 31 year-end would have to file by March 31. Exception: If you’re a sole proprietor (individual) with a Dec 31 year-end, you actually have until June 15 to file the annual GST/QST return (aligned with personal tax filing), but any balance owing must be paid by April 30.

·      Payment Deadlines: Filing and payment are generally due at the same time (one or three months after period-end). Even if you file annually and get the June 15 filing extension as an individual, the payment due date remains April 30 for that year. Missing a payment will incur interest, so it’s crucial to pay on time.

·      Even if No Activity: Remember, you must file a return for each period even if you had no sales or no tax to remit (this would be a nil return)c. For instance, a startup with no revenue in Q1 still needs to file a Q1 return showing zero owing. Mackisen can file nil returns quickly on your behalf to keep you compliant.

Staying on top of these deadlines is vital. Mackisen’s system will alert us (and you) of upcoming due dates. We’ve had clients come to us after missing filings – we helped them catch up and often negotiated relief of some penalties by demonstrating good faith. It’s always better, though, to file accurately and on time with professional help.

Calculating GST and QST (and Maximizing Credits)

Calculating how much GST/QST to remit can be boiled down to a simple formula: Tax collected on sales minus tax paid on expenses = net tax payable (or refund). Here’s what that entails:

·      GST/QST on Sales: As of 2025, GST is 5% federally, and QST is 9.975% in Québec. These rates apply on most taxable supplies of goods and services. (Some items are zero-rated or exempt – e.g., basic groceries are exempt from GST/QST). In practice, if you sell a taxable item for $100, you would charge $5 GST and $9.98 QST, for a total of $114.98 to the customer. (Note: QST is not charged on the GST – it’s calculated on the sale price alone since 2013, although the combined effect is still roughly 14.975% of the price.)

·      GST/QST on Expenses: The GST and QST your business pays on its purchases and operating expenses can largely be recovered. For GST, these refunds are called Input Tax Credits (ITCs); for QST, they are called Input Tax Refunds (ITRs). Essentially, if you paid GST/QST on something used in your business (e.g. inventory, equipment, rent), you get to subtract those amounts from the tax you owe on salesan.com. Registrants claim ITCs and ITRs when they file their GST/QST returns for the period, effectively getting a refund or offset.

·      Net Tax Payable or Refund: After adding up all GST/QST collected and subtracting all ITCs/ITRs, you arrive at your net tax for the period. If the result is positive, that’s what you remit to Revenu Québec. If it’s negative (i.e., you paid more GST/QST on purchases than you collected on sales), you get a refund. Revenu Québec will either apply it to any other tax debts or issue you the balance. Mackisen ensures all calculations are correct and that you claim every dollar of credit you’re entitled to, so you never pay more than necessary. We also cross-check that your figures align with your financial statements to avoid red flags in case of an audit.

It’s worth mentioning that small businesses have the option to use the Quick Method of Accounting for GST/QST, which simplifies how tax is remitted (you remit a fixed percentage of sales rather than tracking all credits). This can reduce paperwork, but it’s not beneficial for everyone. We can advise if the Quick Method is right for you; either way, we handle the math and ensure the method you use is optimal for your situation.

Filing Methods: Online through Revenu Québec (My Account)

Gone are the days of mailing paper GST/QST returns. Revenu Québec now requires nearly all businesses to file electronically for periods in 2024 and later. The good news is that electronic filing is faster and provides immediate confirmation.

The main ways to file your GST/QST return online include:

·      Revenu Québec's “My Account for businesses” (Mon dossier pour les entreprises): This is the primary online portal for Quebec business taxes. Through Mon dossier (accessed via the secure login clicSÉQUR), you can file returns, make payments, and view your past filings. Mackisen often files clients’ returns through this portal as authorized representatives. It’s convenient and integrates both GST and QST reporting.

·      Online Express Services: Revenu Québec offers a GST/QST express filing service where you can quickly submit a return using an access code (for instance, if you don't want to fully log into My Account). This is handy for very small businesses or those who just want to file a simple nil return.

·      Authorized Software or Financial Institution: Some accounting software can transmit GST/QST returns directly, and certain financial institutions' online banking allow filing while making payment. We ensure any software is properly set up if you prefer that route, or we handle the filing for you through our professional software.

·      Paper (limited cases): As of now, only specific exceptions (like certain charities or special cases) can file paper returns. For example, registered charities can use a form FPZ-500.AR-V if Revenu Québec mails it to them, but even then they are encouraged to file online. In general, assume you need to file online. Mackisen will navigate all online filing steps – you won’t have to worry about logging in or technical glitches.

Tip: Always keep a copy of what you filed (electronically this means saving confirmations or PDFs). When we file for you, we provide full documentation. This is important in case of any discrepancy or audit down the line – you’ll have proof of compliance.

What If You Make a Mistake or Miss a Filing?

Despite best efforts, mistakes can happen – maybe an invoice was left out, or perhaps you missed a filing deadline during a busy season. Here’s where having Mackisen as your partner really pays off:

·      Corrections and Amendments: If you realize something was wrong after filing (over-reported sales, under-claimed ITCs, etc.), an amended return can be filed. In fact, Revenu Québec has a specific form (FPZ-2500-V) to amend a GST/QST return. We handle amendments regularly and can communicate with Revenu Québec to adjust the record as needed. Prompt correction can also help avoid penalties.

·      Late Filings: If a deadline passes, it's crucial to file as soon as possible afterward. The penalties often increase with time. We prioritize late filings to limit exposure. We can also request penalty relief in some cases, especially if you had a reasonable cause. (We’ve successfully obtained waivers of late penalties for clients by presenting a solid case – one of the benefits of having tax lawyers and experienced negotiators on our team.)

·      Audits or Notices: Sometimes Revenu Québec or CRA will send a notice or start an audit asking for backup documentation (common if they see discrepancies or if you consistently claim large refunds). Should this happen, Mackisen will stand by your side. We’ve handled many GST/QST audits and have a strategy to defend your filings. From organizing your receipts to making legal arguments, we ensure you’re represented by experts so you don’t face it alone.

The key takeaway is that filing GST/QST doesn’t have to be a source of anxiety or confusion. With a solid understanding of the basics and the right partner to manage the details, you can easily meet your Revenu Quebec business taxes obligations and even turn them to your advantage (through input tax credits and proper planning).