GST and QST
The right taxes on your invoices for the customer’s province, and the quick method compared with the regular method.
For Québec’s self-employed and landlords
Your business books, kept with your AI.
AI agents to understand and manage your business’s books. Cartabel brings your accounts, receipts, invoices and buildings together, with the tax laws of Québec and Canada: all the context they need.
- Add to ChatGPT soon
- Add to Claude soon
In the works. Private beta by invitation.
How much should I set aside for GST and QST this quarter?
So far this quarter, set aside $2,288.18: $764.00 of GST and $1,524.18 of QST, due by January 31, 2027.
| October 1 to November 12 | GST | QST |
|---|---|---|
| Collected on your invoices | $920.00 | $1,835.40 |
| Paid on your purchases, receipts in hand | −$156.00 | −$311.22 |
| To remit | $764.00 | $1,524.18 |
Julie, graphic designer · from her invoices and receipts · regular method
Your AI
AI agents that manage your books.
Connect ChatGPT or Claude: they sort your transactions, check your receipts, and prepare your invoices and your GST, QST and income tax figures. Nothing changes without your approval.
- Add to ChatGPT soon
- Add to Claude soon
ChatGPTRead and change · used todayRemove
ClaudeRead only · used November 9Remove
A connected AI can never move money, connect a bank, export your data or delete your account.
Julie’s connections, graphic designer
The tax laws
Give your AI the laws that apply.
Your AI looks up the tax laws of Québec and Canada, including Québec’s Taxation Act (Loi sur les impôts) and its Act respecting the Québec sales tax, and cites the section that answers.
14 acts and regulations, about 33,000 passages, searched by meaning. It is information drawn from the law, not advice: the decision is yours.
Can I deduct part of my rent for my home office?
Yes, if that room is your principal place of business, or if you use it only for your business and meet clients there on a regular basis. The amount can’t exceed the business’s income, and in Québec a further limit applies.
Taxation Act (Québec), ss. 175.4 and 175.5Income Tax Act, s. 18(12)
Julie, graphic designer, works from home
Your documents
Keep your receipts and invoices in one place.
Drop them in as photos or PDFs, several at once. The AI reads the supplier, the GST and the QST in the background, then links each receipt to its bank line. Your suppliers’ bills, your leases and your statements too.
Quincaillerie de l’Exemple Read in the background
Receipt · November 4, 2026 · no. 48213
Subtotal$214.60
GST$10.73
QST$21.41
Total$246.74
Supplier’s GST and QST numbersread
linked to
QUINC. DE L’EXEMPLEBusiness Visa ••4412 · Nov 4−$246.74 Linked
Marc, plumber
To review
Make fewer mistakes at tax time.
A business purchase on your personal card, a missing receipt, equipment to classify: they wait for you in one place, before they turn into mistakes on your return.
Fournitures de l’ExemplePersonal card · Nov 3$89.99
A business expense?
BusinessNot business
Gas stationBusiness Visa · Oct 2$72.40
Missing receipt
Add the receipt
LaptopBusiness Visa · Oct 28$1,899.00
Equipment to depreciate, or an expense for the year?
Choose
Julie, graphic designer
Your sales tax and income tax
Get to tax time with your figures ready.
The GST and QST to remit, what to set aside for income tax, and the T2125 and TP-80 lines, ready to copy into your tax software.
This quarter’s GST and QST
GST to remit$764.00
QST to remit$1,524.18
Due dateJanuary 31, 2027
Set aside for income tax this month$1,150.00
T2125 and TP-80
Gross business incomeT2125, line 8299$72,400.00
Net incomeT2125, line 9946$48,950.00
The same figures for the TP-80, line by line.
Fill in my return
Julie, graphic designer
Your buildings
Track your rents, unit by unit.
Your units, leases and rents, found in your transactions. Late rent is flagged, and at year end you have the T776 and TP-128 figures and the list for the RL-31.
November rents
Unit 1Lease until June 30, 2027$1,350.00 Paid on the 1st
Unit 2Lease until June 30, 2027$1,280.00 Late · 11 days
Year end
The T776 and TP-128 for Sophie and for Karim, each with their share, and the list for the RL-31: 2 units.
Sophie and Karim, owners
Your invoices
Let your AI prepare your invoices.
Ask for one in a sentence: the draft comes with GST and QST. Nothing is issued until you approve it.
Make an invoice for Café de l’Exemple: menu design, $650, and posters, $280, due in 30 days.
The draft is ready. Shall I issue it?
Invoice · draft To approve
Café de l’Exemple · due December 12, 2026
Menu design$650.00
Posters$280.00
GST 5%$46.50
QST 9.975%$92.77
Total$1,069.27
IssueEdit
Julie, graphic designer
Your control
Choose what your AI can do.
Read only, or read and change: you decide for each AI, and you take its access away whenever you like.
- A preview before every big change.Deleting a transaction, or creating or turning off a rule, takes two steps: the preview, then your confirmation.
- Your AI can’t move money.Nor connect a bank, export your data or delete your account.
- Your data is hosted in Canada.With Microsoft Azure: the app and your documents in Québec City, the database in Toronto. The app’s AI may process your documents outside Canada, and what your AI reads goes to the company you chose, under its terms.
- No bank password, ever.Connect your bank through Plaid (United States), in its own window, or import your statements yourself.
- Your data is never sold.No ads. Leave whenever you like, with your data.
Your AI suggests
File “Hydro-Québec” under “Duplex, 123, rue de l’Exemple”
24 transactions, from January 2025 to November 2026, and future ones
ConfirmCancel
Nothing changes until you confirm.
Québec
Is it made for Québec?
Right down to your taxes.
Revenu Québec’s forms
The TP-80 and TP-128 beside the T2125 and T776, and the list for the RL-31.
Local businesses
Hydro-Québec, Vidéotron and dozens of other local businesses are sorted for you. For the others, the app relies on the Registre des entreprises du Québec.
Questions
More questions?
Can I use it today?
Not yet. The version for the self-employed and landlords is in the works. Access will be by invitation, during a private beta.
Which AI can I connect?
An AI that accepts MCP connectors, like ChatGPT or Claude. You add the app in your AI’s settings, then choose what it can do: read only, or read and change. You can take its access away at any time.
What does my AI know about tax law?
The app gives it access to the tax laws of Québec and Canada: 14 acts and regulations, including Québec’s Taxation Act and Act respecting the Québec sales tax, the Income Tax Act and the GST part of the Excise Tax Act. Your AI searches them for the passages that answer your question and cites the section.
It is information drawn from the law, not advice: you decide.
Who answers my questions, exactly?
Your own AI, if you connect one: there is no chat in the app.
The app’s AI, for its part, works in the background: it reads your receipts and invoices. Your transactions are sorted by your rules, your bank’s category and the Québec businesses we know; whatever is left, you or your AI sort in one tap. It is an OpenAI model, run and protected in Microsoft Azure. OpenAI does not receive your data, and it is not used to train the AI. It may be processed outside Canada.
Does it work with my bank?
If your bank or credit union lets you download your statements as OFX, QFX or CSV files, yes. Look for the download option on your bank’s website, often near your transaction history.
You can also connect your bank through Plaid: your transactions then arrive without you downloading anything. A PDF statement works too: its lines are read in the background, and they must add up to the statement’s own totals.
My business expenses go on my personal card. Is that a problem?
No. Add the card: each purchase goes to your business, to a building, or to “not business”. The ones that look like business expenses are suggested to you in “To review”. Your personal purchases count in no total.
Will you ask for my bank password?
Never. If you connect your bank, you sign in in Plaid’s window: your password never goes through the app. You can also import your statements yourself.
Where is my data stored?
Your data is hosted in Canada: the app and your documents in Québec City, the database in Toronto, with Microsoft Azure. No ads, and your data is never sold.
Does it help with my Québec taxes?
Yes. The app prepares the T2125 and TP-80 figures if you’re self-employed, the T776 and TP-128 figures if you rent out a unit, line by line, and the list for the RL-31. It also compares the two GST and QST methods.
You enter those figures in your tax software: the app does not file the return for you, and it gives no tax advice.
Can I take my data with me?
Yes. Export it whenever you like, and delete your account and your data whenever you like.
Keep your time for your clients and your tenants.
The private beta will be by invitation. Leave your email and we’ll write to you when your spot is ready.
In the works.