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To reverse the taxes on a Quebec price, divide the total by 1.14975 to get the price before tax. That works because Quebec charges 5% GST and 9.975% QST, both on the same pre-tax amount, which adds up to 14.975%.
We’re assuming that’s what “reverse taxes” means here: you have a receipt total with tax already in it and you want the parts back. If you meant something else, such as a reverse charge on imported services, this page won’t help.
How do you reverse taxes in Quebec?
Start from the amount paid, which is the figure on the card slip or the invoice total, with both taxes already inside it. Divide it by 1.14975 and you have the base price. Multiply the base by 5% for the GST and by 9.975% for the QST. Both taxes come off the same base, so the QST never applies to the GST.
Take a $250 total. Divide by 1.14975 and the price before tax is $217.44. GST is $10.87 and QST is $21.69. Together the tax is $32.56, and $217.44 plus $32.56 gives back your $250.
| Line | Amount |
|---|---|
| Total paid | $250.00 |
| Price before tax | $217.44 |
| GST (5%) | $10.87 |
| QST (9.975%) | $21.69 |
Our reverse sales tax calculator does the division for you, and the GST and QST calculator goes the other way, from a pre-tax price to a total.
Why can’t you subtract 14.975% from the total?
Because the percentage is taken from the wrong number. Fourteen point nine seven five percent of $250 is $37.44, which would leave $212.56. That’s off by almost five dollars, on one small purchase, and you’d carry that same slip into every receipt after it. The tax was added to a smaller price, so division is the only step that undoes it.
It’s the most common slip in reverse tax work, and the error grows with the amount. On a $5,000 invoice, subtracting instead of dividing misstates the tax by about $100.
Does rounding change the answer?
A little. Each tax is rounded to the cent on its own, so the parts can differ from a total by a cent. Revenu Québec allows the QST rate to be shortened to 9.97% only when a cash register can’t handle three decimals, per its page on calculating the taxes. If you keep the books, use 9.975%. A receipt from a merchant that uses the full rate can still round differently from yours by a cent, and that’s normal.
When would you need this in real life?
Three cases come up. You have an expense receipt and want the tax portion for your records. You’re a sole proprietor pricing a job and want to know the pre-tax amount for a flat quote. Or you’re checking a bill from a supplier. If you work for yourself, the self-employed tax calculator is the next stop for the income tax side.
Mind the difference between the tax you paid and the tax you can claim back. Businesses registered for the taxes can often recover them on costs, but the rules and limits sit with the CRA and Revenu Québec, and we haven’t confirmed the details here. Ask your accountant which of your purchases qualify, because a receipt total alone doesn’t show that.
What are the limits of this method?
It applies to a price taxed at the full 5% and 9.975%. Some goods and services are zero-rated or exempt, so no tax is in the total, and dividing by 1.14975 would wrongly shrink the price. Check the receipt for a GST and a QST line first.
Prices outside Quebec need another factor. In Ontario the tax is a single 13% HST, so you divide by 1.13.
Where do the numbers come from?
The 5% GST and 9.975% QST rates are the ones listed in our data files and described on Revenu Québec’s page on calculating the taxes. The worked example is our own calculation.
Frequently asked questions
How do I remove GST and QST from a Quebec price?
Divide the total by 1.14975. The result is the price before tax.
What are the Quebec sales tax rates?
5% GST and 9.975% QST, both charged on the pre-tax price.
Why can't I subtract 14.975% from the total?
Because the tax was worked out on the smaller pre-tax price. Subtracting takes the percentage of the larger total and gives the wrong answer.
Does the QST apply on top of the GST?
No. Both are calculated on the same pre-tax amount.
Will my result match the receipt to the cent?
Usually, but each tax is rounded on its own, so it can differ by a cent.
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Information only. This page is general information, not tax, legal or accounting advice. Tax-Services.ca is an independent publisher: we don't prepare or file tax returns or offer tax services, and we have no connection with the CRA, Revenu Québec, any government or any company named on this page. Check the figures that matter with an official source or a qualified professional.