The Small Business Deduction: The 9% Rate, the $500,000 Limit and the Grinds
the 9% rate, the shared $500,000 limit and the taxable-capital and passive-income grinds
The small business deduction (SBD) reduces the federal corporate tax rate to 9% on the first $500,000 of active business income earned by a Canadian-controlled private corporation, against a general federal rate of 15%. The $500,000 business limit is shared among associated corporations, and it is ground down where the group's taxable capital or passive investment income exceeds set thresholds.
What is the small business deduction?
A rate reduction that cuts the federal corporate tax rate to 9% on the first $500,000 of active business income earned in Canada by a Canadian-controlled private corporation. Income above the limit — and all income of non-CCPCs — pays the 15% general federal rate.
Provinces layer their own rates on top, most with a reduced small-business rate that broadly parallels the federal structure. The deduction is claimed on the T2, where the business limit, its allocation among associated corporations and its grinds are all worked out on the return's schedules.
Which corporations qualify for the SBD?
A corporation that is a Canadian-controlled private corporation throughout the year, earning active business income in Canada. Private, resident in Canada, and not controlled by non-residents or public corporations — lose CCPC status for part of the year and the deduction goes with it.
The income test matters as much as the status test. Investment income does not qualify. Income of a specified investment business — one whose principal purpose is earning property income, with limited staff — does not qualify. Income of a personal services business, the incorporated-employee pattern, is excluded and taxed at a higher federal rate. The SBD is for operating income.
How is the $500,000 business limit shared?
Associated corporations share one $500,000 business limit and file an agreement allocating it among the group on Schedule 23 of the T2. The limit is prorated for short tax years. Two corporations controlled by the same person do not get $1,000,000 between them.
Provincial small-business limits are set separately and mostly mirror the federal amount, but not universally — and Québec applies its own eligibility tests to its provincial small-business rate, including a minimum-hours requirement, so a corporation can qualify federally and still miss provincially. Check each province's current rules rather than assuming the federal result carries over.
How does taxable capital reduce the business limit?
The limit shrinks on a straight-line basis where the associated group's taxable capital employed in Canada exceeds $10 million, disappearing entirely at $50 million. The upper bound was extended from $15 million to $50 million for tax years beginning on or after April 7, 2022.
Taxable capital is a balance-sheet measure, so a capital-intensive client can grind its limit while its income stays modest. Because the test runs at the associated-group level, the calculation needs the whole group's figures — another reason the firm's records should map who is associated with whom before season, not during it.
How does passive investment income reduce the limit?
Where the associated group's adjusted aggregate investment income in the previous year exceeds $50,000, the business limit falls by $5 for every $1 of excess — reaching zero at $150,000 of investment income. A corporation sitting on a large passive portfolio can lose the deduction entirely.
The limit that applies is the lesser of the two grinds' results, not their sum. And not every province parallels the federal reductions, so a corporation can lose the federal small-business rate while keeping a provincial one. The planning conversations — portfolio location, corporate structure, dividends — belong months before year-end, while there is still a year to act in.
How does the SBD change the T2 payment deadline?
Claiming the deduction changes the payment clock. A corporation's balance of tax is generally due two months after year-end, but eligible CCPCs claiming the small business deduction get three months — the return itself stays due at six months either way.
The three-month rule carries its own conditions on income and status, so a client that loses the SBD can also quietly lose a month on its payment deadline — a second, less obvious cost of crossing a threshold. A firm tracking balance-due dates per client should treat SBD status as an input to the deadline, not a separate fact.
| Filing | Applies to | Filing deadline | Payment | If it is late |
|---|---|---|---|---|
| T2 corporation income tax return | Every resident corporation, every tax year, even with no tax payable. | File within six months after the end of the corporation's tax year. Where the year-end is the last day of a month, the return is due the last day of the sixth following month; otherwise it is due the same day of the sixth month. | The balance of tax is due earlier than the return: generally two months after year-end, or three months for eligible Canadian-controlled private corporations claiming the small business deduction. Filing on time is not paying on time. | 5% of the unpaid tax plus 1% per complete month late, to a maximum of 12 months. Repeated failure raises it to 10% plus 2% per month for up to 20 months. |
How firms track SBD exposure across a corporate book
Track the thresholds, not just the rate. The firms that catch grinds early keep three facts current for each corporate client: the associated group it belongs to, the group's taxable capital, and last year's investment income — reviewed on a schedule, not on discovery.
In SpidNums, admin-defined custom fields hold group membership and threshold flags on the Client CRM record, corporate tax sits in the Services catalogue on each client's year-end cadence, and the annual SBD review is an ordered task on the year-end project in Task Master. Reminders keeps that work surfacing a month ahead of each fiscal year-end.
Frequently asked questions
What is the small business deduction rate?
The small business deduction reduces the federal corporate tax rate to 9% on the first $500,000 of active business income of a Canadian-controlled private corporation, compared with the 15% general federal rate. Provinces set their own corporate rates on top, most with a parallel reduced small-business rate, so the combined rate depends on the province.
Do associated corporations each get their own $500,000 limit?
No. Associated corporations share a single $500,000 business limit and file an agreement on Schedule 23 of the T2 allocating it among the group. Association is defined by control relationships, so two corporations controlled by the same person or group are caught. The limit is also prorated where a tax year is shorter than a full year.
What income does not qualify for the small business deduction?
Investment income, income of a specified investment business, and income of a personal services business do not qualify — the deduction applies only to active business income earned in Canada by a Canadian-controlled private corporation. Personal services business income, the incorporated-employee pattern, is also taxed at a higher federal rate than ordinary corporate income.
How does passive income reduce the small business deduction?
Where an associated group's adjusted aggregate investment income for the previous year exceeds $50,000, the federal business limit is reduced by $5 for every $1 of excess, reaching zero at $150,000. The taxable-capital grind runs in parallel, and the corporation's limit is the lesser of the two results. Not every province parallels these federal reductions.
Does the small business deduction change when corporate tax is due?
It changes the payment deadline, not the filing deadline. Eligible Canadian-controlled private corporations claiming the small business deduction generally have three months after year-end to pay their balance of tax instead of two. The T2 return remains due six months after year-end in both cases, so the SBD effectively buys an extra month on the money.
Related guides
How firms run this
By province
Turn these dates into tickets.
SpidNums generates the work from each client's cadence and year-end, then ranks it by proximity.