Overview
Many Canadian-controlled private corporations (CCPCs) can access a lower corporate tax rate on the first slice of active business income, but only up to a “small business limit.” Most people think of it as the first $500,000 of active business income; in practice the limit can be shared, reduced, or eliminated depending on your corporate structure, your size, and your passive investment income.
CRA reference: How certain relationships affect the small business deduction (SBD)
Common reasons the limit disappears or shrinks:
- Associated corporations (you must share one limit across the group)
- Taxable capital (taxable capital higher than a certain amount grinds down the SBD limit)
- Passive investment income (AAII) (passive income higher than a threshold grinds down the limit)
- Ineligible business types (e.g., personal services business; specified investment business unless an exception applies)
What is the small business limit
Small business limit vs. Small Business Deduction (SBD)
The small business limit is the cap on income that can qualify for the Small Business Deduction (SBD). Under Income Tax Act (ITA) section 125, a CCPC’s business limit is generally $500,000 for the year (subject to the sharing and reduction rules below).
Detailed rules
1) Basic eligibility: CCPC + active business income in Canada
To access income taxed at the small business rate, you generally need:
- A corporation that is a CCPC throughout the year
- Active business income carried on in Canada that qualifies for the SBD (not all business income qualifies)
Common exclusions from SBD eligibility:
- Personal services business (PSB) income (see this Blog for more details about PSB)
- Specified investment business (SIB) income (generally), unless an exception applies
2) Default business limit: $500,000 (but it can be nil without allocation in an associated group)
ITA 125(2) sets the general rule: the business limit is $500,000 unless the CCPC is associated with other CCPCs; in that case, the corporation’s business limit is nil unless the group allocates the $500,000 among themselves under the Act’s associated-corporation mechanism. For detailed discussion about the association rules read this Blog).
3) Sharing rules: associated corporations must share one limit
If corporations are associated (generally determined under ITA section 256 plus related/arm’s length concepts), the group shares a combined business limit of $500,000 (before reductions).
Associated CCPCs generally file an allocation agreement on T2 Schedule 23.
Example
- Companies A and B are associated CCPCs.
- A earns $300,000 of eligible active business income.
- B earns $400,000 of eligible active business income.
Even though each company’s active business income is lower than the $500,000 small business limit, the group can only apply the small business rate to $500,000 combined. They must allocate the $500,000 between A and B using Schedule 23.
4) The size grind: taxable capital can reduce the business limit
Even with eligible active business income, the business limit can be reduced when taxable capital employed in Canada (generally including associated corporations) is too high.
Generally:
- Phase-out begins when taxable capital exceeds $10 million
- Eliminated at $50 million
Example:
If a corporation has $30 million taxable capital employed in Canada, it loses 50% of its small business limit: $20M excess capital / ($50M-$10M) = 50%
SBD = $500,000 * 50% = $250,000
5) The passive income grind: AAII can reduce the business limit
The business limit can be reduced based on Adjusted Aggregate Investment Income (AAII) earned by the CCPC and its associated corporations. Once AAII exceeds $50,000, the business limit is reduced; it is fully eliminated at $150,000 of AAII (group basis). CRA also notes the AAII reference year is generally taxation years ending in the preceding calendar year.
What is AAII?
Adjusted Aggregate Investment Income (AAII) is the measure of “passive investment income” that the Income Tax Act uses to determine whether a CCPC’s small business limit gets ground down under the passive-income rules. It’s defined in ITA subsection 125(7).
In plain terms: AAII is (mostly) your corporation’s net investment income, with some specific inclusions/exclusions and adjustments, and it’s computed each taxation year and then used (together with associated corporations) to reduce next year’s business limit.
What income is included in AAII?
AAII generally includes all investment-type amounts such as:
- Interest and other income from property
- Net rental income
- Net taxable capital gains (taxable gains minus allowable capital losses, broadly)
- Royalties
- Portfolio dividends (generally dividends that are investment income rather than dividends from connected operating subsidiaries)
Key exceptions and special cases
Specified investment business (SIB): the rental/investment trap (with a staffing exception)
A specified investment business is generally a business whose principal purpose is to derive income from property (interest, rent, dividends, royalties, etc.). It is generally not eligible for the SBD unless an exception applies (commonly referenced as employing more than five full-time employees throughout the year or equivalent rules through associated corporations).
Personal services business (PSB)
If CRA considers your corporation a personal services business, its income is not eligible for the SBD and can be subject to additional tax and restricted deductions.
Common pitfalls
- “We have two corporations, so we get $1,000,000 of small business limit.” (Usually false if the corporations are associated.)
- Forgetting Schedule 23 (or filing it inconsistently) for an associated group.
- Ignoring passive income inside the corporation (AAII grind).
- Assuming rental income is always “active business income” (SIB risk).
- Not realizing the AAII test and presume it looks to be the same as preceding calendar year (timing surprises).
How to protect the SBD
Generally, you need to monitor all eliminating and reducing measures during the year, including:
- Avoid being ineligible in the fist place. Two common examples:
- PSB (Personal Services Business)
If you’re effectively an incorporated employee, PSB income doesn’t qualify for the SBD and the rules are punitive. Clean contract terms, multiple clients, business risk, and operational substance matter.
- SIB (Specified Investment Business)
If the business mainly earns income from property (e.g., many rental corps), SBD is generally blocked unless exceptions apply (like staffing).
- Manage AAII (passive income)
The goal here is to keep the AAII under $50,000 to utilize the full small business limit.
Strategies that move the needle:
- Timing strategies:
- Timing matters because the reduction is based on the AAII for the taxation year ending in the preceding calendar year.
- Realize capital losses, where available, to reduce capital gains.
- Defer dispositions that would trigger large capital gains.
- Reduce the investments that generate passive income or move the investment outside of the corporation if AAII is close to the threshold.
- Control association risk
Association rules are complicated. The goal is to avoid accidentally becoming associated with other corporations.
- Monitor taxable capital
The goal is to stay below the $10M limit
FAQ
Is the small business limit always $500,000?
It’s the starting point under ITA section 125, but it can be shared, reduced, or eliminated due to association, taxable capital, and AAII.
If I have a Holdco and Opco, do I get two limits?
If they’re associated, they generally share one limit and must allocate it (Schedule 23).
Does investment income inside the corporation affect my small business rate?
Yes. AAII can reduce the business limit once it exceeds the threshold described by CRA.
Are professional corporations automatically safe?
No. They can still be associated with other corporations, can earn AAII, and may face PSB risk depending on facts.
Where do I see this in the T2 return?
Common schedules include Schedule 7 (SBD calculations) and Schedule 23 (allocation among associated CCPCs).
Need Help?
If your corporation (or group) is approaching $500,000 of active business income, building an investment portfolio inside the corporation, or using multiple corporations (Opco/Holdco/real estate/management entities), you should model your small business limit before year-end decisions lock in.
Book a call with Finsight CPA Inc. to review:
- your associated corporation structure and allocation requirements
- taxable capital exposure
- AAII and passive income trajectory
- PSB/SIB risk areas and clean-up opportunities