Quick answer: The half-year rule is the CCA convention that, in the year you buy a depreciable asset, you may generally claim capital cost allowance on only half of the net additions to the class — as if the asset had been owned for six months regardless of the purchase date. A Class 8 asset at 20% therefore yields a 10% first-year claim. Accelerated investment incentives have at times suspended the rule for eligible property; the CRA’s CCA pages state which years and classes.
What the half-year CCA rule does
Capital cost allowance is the tax version of depreciation: rather than deducting the cost of a truck, a computer or a piece of equipment in the year you buy it, you deduct a percentage of the pooled balance of its class each year. The half-year rule is a first-year adjustment to that pool. In the year of acquisition, the amount on which you calculate CCA is reduced by half of the net additions to the class — purchases less dispositions — so the first year’s claim is roughly half of what the class rate would otherwise give.
The effect is easiest to see on one asset. Buy a $10,000 Class 8 asset (20% declining balance) in a year with no other additions or disposals: the half-year rule reduces the amount subject to CCA to $5,000, so the first-year claim is $1,000 rather than $2,000. The unclaimed $1,000 is not lost; it stays in the undepreciated capital cost of the class and is claimed over the following years at the full rate.
Why it exists
Without it, an asset bought on 30 December would earn a full year of CCA for one day of ownership. The rule assumes, on average, that assets are bought halfway through the year, and it applies that assumption to everyone rather than tracking purchase dates asset by asset. It is a simplification that favours the CRA slightly in year one and the taxpayer slightly thereafter.
When it does not apply
- Accelerated investment incentive property. For eligible property acquired within the incentive’s window, the half-year rule is suspended and the first-year claim is enhanced rather than halved. The incentive has a phase-out schedule; whether a given purchase qualifies depends on the acquisition date and the class. The CRA’s CCA pages carry the current table — do not assume the enhanced treatment still applies to this year’s purchase without checking.
- Immediate expensing. Where a corporation elected immediate expensing on qualifying property in the years that measure was available, the property was written off in full and no half-year adjustment arose.
- Certain classes and situations. A handful of classes are excluded from the rule by regulation, and property acquired in a non-arm’s-length transaction that was already depreciable to the seller is treated differently. These are exceptions your accountant checks class by class.
What it means for a purchase decision
The rule rarely changes whether to buy an asset, but it does change when the tax deduction lands. A purchase made in the last month of the fiscal year still earns the half-year claim for that year, which is why year-end equipment purchases are a legitimate timing decision rather than a trick — provided the asset is available for use before the year end, which is its own test. A purchase made the first week of the following year earns nothing for the year just closed.
| Treatment | Base for year one | First-year CCA at 20% |
|---|---|---|
| Half-year rule applies | $5,000 | $1,000 |
| No half-year rule (illustrative only) | $10,000 | $2,000 |
| Accelerated investment incentive, where eligible | enhanced — per the CRA table for the acquisition year | more than $2,000 |
The figures are the rule applied to a round number, not a projection for any business; which line applies to a real purchase depends on the class, the date and the current incentive schedule.
Related
CCA classes explained · Equipment CCA classes · Immediate expensing · Glossary
Sources: CRA — Basic information about capital cost allowance · CRA — T4012 T2 Corporation Income Tax Guide. General information, not advice.
A farm example
An Abbotsford berry farm buying a harvester in the last month of its fiscal year still earns the half-year claim for that year, provided the machine is available for use before the year end — which for seasonal equipment delivered off-season is a question worth asking before the invoice date is chosen. Farm accountant in Abbotsford.
The half-year rule is applied on the CCA schedule of the year the asset is bought; T2 preparation includes the timing of large purchases around year-end.
Frequently asked questions about the half-year rule
Does the half-year rule apply to a used asset?+
If I buy in December, do I still get the half-year claim?+
Is the half of the cost I could not claim lost?+
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The rule is simple once stated; what the rule means for a real purchase decision shows it deciding an actual buy-now-or-wait question.
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