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Carbon credit bookkeeping comes down to one habit: treat each credit like a tracked asset with a paper trail. In Canada’s federal system one offset credit equals one tonne of carbon dioxide reduced or removed, so your records should show how many tonnes you hold, where they came from, and what happened to each one.
What counts as a carbon credit in Canada?
Environment and Climate Change Canada runs the federal Greenhouse Gas Offset Credit System. Project developers register a project under the regulations and one of the federal protocols, and credits are tracked in a public registry. The protocols open for applications cover landfill methane, refrigeration systems, improved forest management on private land, beef cattle methane and manure methane.
Each offset credit is equivalent to one tonne of carbon dioxide reduced or removed from the atmosphere.
Canada’s Greenhouse Gas Offset Credit System, canada.ca
Some provinces run their own systems, and those can differ. Your bookkeeping starts from whichever registry issued the credit.
Which records should you keep for every credit?
| Record | Why it matters |
|---|---|
| Registry serial numbers and issuance statement | Proves the credit exists and who held it |
| Purchase invoice and payment proof | Supports the cost and any sales tax you paid or self-assessed |
| Verification report or project documents | Shows the tonnes were verified, if you are the project owner |
| Transfer or retirement confirmation | Shows the credit left your books |
| Date of each step | Fixes the tax period for GST/HST and income |
Keep all of it for at least six years from the end of the last tax year it relates to. That’s the CRA’s general retention rule, and it’s the safe default here.
In practice, one line per batch in a simple register does the job. Something like: 100 credits, serial range from the registry, bought on a given date for $2,000, so $20 each, and a blank column for the day they’re retired. When the retirement confirmation arrives, you fill it in and attach the PDF.
How does GST/HST treat carbon credits?
This is where the paperwork matters most. The CRA has said that emission allowances, and that includes emission performance credits, emission offsets and sequestration credits under Alberta’s TIER regulation, fit the definition in the Excise Tax Act. The first sale by a Canadian government body is generally exempt from GST/HST.
Since June 27, 2018, a buyer who has to pay tax on an emission allowance self-assesses it instead of the seller collecting it. The buyer then reports it on its own return and claims input tax credits where it can. The Department of Finance’s 2018 release on emission allowances says the purchaser is responsible for self-assessing the tax.
Here’s what that looks like. Say you buy credits for $2,000 in Ontario. If 13% tax applies, the GST/HST calculator shows $260 of HST. The rule that decides whether it applies to your particular purchase is fact specific, so we can’t tell you yes or no from here. Ask the CRA’s GST/HST rulings line if the seller and the type of credit are unusual.
What about income tax?
We couldn’t confirm from an official page if your credits count as inventory, capital property or something else. The answer turns on why you hold them. A business that buys credits to cover its own compliance obligations is in a different spot from a trader, and a farm that earns credits from a project is in a third. This is one place where an accountant who has seen your contracts earns the fee.
Until you get that answer, keep the cost and the intended use written down on the day you buy. Then whoever prepares your return can classify them without guessing.
Once the profit lands, the corporate tax calculator shows what tax looks like on it. An Ontario corporation with $300,000 of active business income owes $35,088 for 2026 in the tool, an average of 11.7%. A sole proprietor can run the same idea through the self-employed tax calculator.
What changes when a credit is sold or retired?
Selling means the credit leaves your register, and the proceeds go through your sales records with the date and the buyer. Retiring means you’ve used it, so it’s gone for good and can’t be sold again. Either way, the registry’s confirmation is your proof, so file it the same day. If you ever resell credits you bought, keep the purchase record next to the sale so the difference is easy to show.
Common bookkeeping mistakes with credits
- Booking the whole purchase as a plain expense with no tonnes or serial numbers behind it.
- Losing the retirement record, so you can’t show a credit was used once.
- Mixing credits from different registries in one line.
- Forgetting the self-assessed tax entry, so the return and the ledger disagree.
Prices move, and we don’t quote them. Record what you actually paid, and don’t write up a market value unless your accountant tells you to. For related tools, browse the sales tax hub.
Where this information comes from
The credit definition and the federal protocols come from Environment and Climate Change Canada’s offset system page. The GST/HST treatment comes from the Department of Finance release of June 2018 and the CRA‘s Excise and GST/HST News, and retention from CRA circular IC78-10. The examples use this site’s 2026 calculators. This is an independent guide, separate from any government body.
Frequently asked questions
What is one carbon offset credit?
In Canada's federal offset system, one credit equals one tonne of carbon dioxide reduced or removed.
Do I charge or pay GST/HST on carbon credits?
The first sale by a Canadian government body is generally exempt. On later purchases the buyer self-assesses the tax where it applies.
Are carbon credits inventory or capital?
We couldn't confirm it from an official page. It depends on why you hold them, so record the purpose on the purchase date.
How long should I keep carbon credit records?
At least six years from the end of the last tax year they relate to, under the CRA's general rule.
Which records prove a credit?
Registry serial numbers, the issuance statement, the invoice and payment proof, and the transfer or retirement confirmation.
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