I automated my GST/QST returns: from 4 hours to 15 minutes a quarter
I file my company's GST and QST returns myself. Each quarter took me about 4 hours. I built a private dashboard that reads my invoices and receipts, reconciles my bank statements and calculates the lines of the return, ready to copy into Revenu Québec's online portal. Now it takes about 15 minutes.
101Supplies (revenue)$24,000.00
GST
103GST collectible$1,200.00
106ITCs$86.40
113Net GST$1,113.60
QST
203QST collectible$2,394.00
206ITRs$172.37
213Net QST$2,221.63
Why do I file my GST/QST myself?
My business is a small corporation in Québec with few transactions: a handful of invoices to one main client, software subscriptions, equipment. At that volume, paying an accountant every quarter didn't make sense, so I chose to file my returns myself, online.
A few rules worth knowing:
- In Québec, Revenu Québec administers both the GST (5%) and the QST (9.975%).
- Under $1.5M in annual taxable sales, the assigned frequency is annual, but you can choose to file quarterly or monthly. I do: I prefer smaller, more regular amounts.
- For quarterly filers, the deadline to file and pay is one month after the end of the quarter.
- Electronic filing is mandatory for periods beginning on or after January 1, 2024.
What took 4 hours?
Not the math. Everything before it: finding receipts scattered across my inbox, downloading bank statements, checking each expense had its tax, separating what's recoverable from what isn't, adding it all up, then copying amounts line by line into the portal.
Four hours a quarter is sixteen hours a year on a task that adds no value, always done at the last minute.
What does the tool actually do?
- I drop in an invoice or receipt as a PDF. A reader recognizes my own invoices and receipts from common suppliers. When it doesn't recognize a document, AI (Claude) suggests the fields: pre-tax amount, GST, QST, total. I approve with one click.
- I import the bank statement as CSV. Transactions are sorted by rules and matched with documents. Possible duplicates are flagged instead of being added twice.
- The quarter calculates itself. The tool fills in the short return, lines 101 to 300, using the regular or quick method, with adjustments when needed.
- I copy and record. I enter the lines in the portal, then record the confirmation number and the payment. A reminder appears 14 days before each deadline.
The tool prepares; I check and file. Nothing goes to Revenu Québec without me.
How much time does it save?
| Before | With the tool | |
|---|---|---|
| Per quarter | ≈ 4 h | ≈ 15 min |
| Per year | ≈ 16 h | ≈ 1 h |
The biggest gain isn't in the table: documents are sorted as they come in, so I always know how much tax to set aside.
What to know before automating
A tool is only useful if the documents it reads are valid. To claim ITCs (GST) and ITRs (QST), an invoice must show certain information depending on its amount:
| Information | Under $100 | $100 to $499.99 | $500 and over |
|---|---|---|---|
| Supplier name, date, total amount | Yes | Yes | Yes |
| Tax amount | QST only | Yes | Yes |
| Supplier's GST and QST registration numbers | No | Yes | Yes |
| Buyer's name, payment terms, description | No | No | Yes |
Thresholds in force since 2021 ($100 and $500). Some older documents still mention $30 and $150.
- Keep your records 6 years after the end of the year they relate to. Electronic format is accepted if it allows accessible, usable copies. Before throwing away scanned paper originals, check the conditions with Revenu Québec or your accountant.
- Suppliers outside Québec. Some foreign online services are registered under a special QST system. If you give them your QST number (the one containing the letters TQ), they must not charge you QST.
- Quick method. Available if your worldwide taxable sales don't exceed $400,000, except for certain professional services (legal, accounting and financial consulting, among others).
What would a tool like this cost?
The version I use is a full Web app: secure login, encrypted data, bank import, investment tracking and dividend planning. At GuiP, that's $5,000 to build and $199 a month.
A focused version that reads your receipts and only prepares the return lines is a Tool: $1,500 to build and $79 a month.
Frequently asked questions
Does the tool replace my accountant?
No. It prepares the numbers and saves time, but the return remains your responsibility. For questions of interpretation, your accountant is still the right person.
Does the AI file the return for me?
No. AI only helps read documents that a simple reader doesn't recognize, and I approve every field. I enter and file the return myself in the portal.
Where is my data stored?
In my case, on a computer I own, encrypted, behind a protected login. For a client, hosting is in Canada whenever possible and data is never used to train an AI model.
Does it work for a business with employees?
Yes, the principle is the same. The sources change: sales, suppliers, payroll. That means more integrations, often a Web app size.
Sources
- Revenu Québec — historique des taux de TPS et de TVQ
- Revenu Québec — périodes de déclaration
- Revenu Québec — modification de la fréquence de déclaration
- Revenu Québec — transmission de la déclaration
- Revenu Québec — préparation des factures
- Revenu Québec — tenue de registres et pièces justificatives
- Revenu Québec — fournisseurs hors Québec, perception de la TVQ
- Revenu Québec — qui peut utiliser la méthode rapide
This article describes my own experience and is not tax advice. Check your situation with Revenu Québec or a professional.
A designer for 25 years, I now build AI tools on subscription for businesses in Québec. I write here about what I learn building them.
