Two IT consulting corporations under the same control, even when they look completely unrelated on paper, generally share one $500,000 small business deduction limit rather than getting $500,000 each. This is the associated corporation rule, and it catches consultants off guard more often than almost any other structural issue, because the businesses involved frequently look nothing alike: an operating consultancy and a numbered corporation that holds a rental property, for instance, or two consultants’ separate CCPCs that occasionally subcontract to each other.
What the Small Business Deduction Limit Actually Protects
The small business deduction reduces the federal corporate tax rate on the first $500,000 of active business income earned by a Canadian-Controlled Private Corporation (CCPC) from the general rate to a preferential small business rate, with a further provincial reduction on top. On $350,000 of active business income, the SBD represents a meaningful reduction in the corporation’s total tax bill for the year, money that would otherwise sit with CRA instead of being available for compensation, reinvestment, or retained earnings.
The $500,000 figure is not per corporation. It is a single limit that applies across an entire group of associated corporations, however many corporations that group contains. A consultant who assumes each corporation they control gets its own fresh $500,000 limit is making an assumption the Income Tax Act does not support.
What Triggers Association
The associated corporation rules live in section 256 of the Income Tax Act and turn on the concept of control, not on how similar or different the businesses are, and not on whether the shareholders intended the corporations to be linked.
Common control by one person. If the same individual controls two corporations, whether by owning a majority of voting shares in each or otherwise, the two corporations are associated. This is the most common trigger for a consultant who incorporates a second entity, a holding corporation for investments or a rental property, without realizing the SBD limit now has to be shared.
Control by a related group. Corporations controlled by the same related group of persons, such as spouses or a parent and adult child, are generally associated even where no single individual controls both alone.
Control by an unrelated group with sufficient overlap. Corporations controlled by the same group of unrelated persons can also be associated, depending on the specific ownership and voting arrangement. This scenario requires closer analysis than the single-controlling-person case, since the degree of overlap in the group and the specific facts determine the outcome.
Deeming rules. Section 256 contains several deeming provisions that can create association even where the plain ownership percentages would not suggest it. Options or rights to acquire shares can be deemed exercised for purposes of the association test. Corporations can be deemed associated with each other through a third corporation they are each separately associated with. These deeming rules are the part of the analysis most likely to produce a result that surprises the parties involved, and they are also the part most dependent on the specific facts of the arrangement.
The Consulting-Firm Scenarios Where This Actually Comes Up
A single consultant with an operating corporation and a holding corporation. A consultant who incorporates a Holdco to accumulate investment income separately from client billings controls both the Opco and the Holdco. They are associated. The $500,000 limit is shared between them, and if the Holdco is also carrying on some form of active business (rather than pure passive investment holding), the allocation of the limit between the two becomes a real planning question, not a theoretical one.
Multiple consultants with individually owned corporations that subcontract to each other. One Corporation or Multiple for a Consulting Firm? covers this structure in the context of choosing between operating models. The association question inside that structure depends on whether any cross-shareholding, profit-sharing, or common-control arrangement exists between the consultants’ separate corporations. Three consultants with genuinely independent corporations, no cross-ownership, and no shared control are not automatically associated simply because they subcontract to one another on client work. But an arrangement that involves one consultant holding equity in another’s corporation, or a side agreement that functions like shared control, changes the answer.
A consultant who also controls a spouse’s corporation. Spouses are a related group for these purposes. A consultant who controls their own consulting CCPC while their spouse controls a separate corporation, where the consultant also has influence or ownership consistent with control, can find the two corporations associated even though the businesses are unrelated and the corporate structures were set up independently.
Allocating the Limit Between Associated Corporations
When corporations are associated, they do not lose the SBD limit entirely. They file Schedule 23, the agreement among associated corporations, allocating the $500,000 limit between them in whatever proportion the group chooses. A group that files no agreement risks having CRA allocate the limit, generally to the corporation’s disadvantage, since the default allocation in the absence of an agreement can assign the full limit to one corporation and leave the other with none.
The allocation is a planning decision, not a formality. A group where one corporation consistently earns close to $500,000 in active business income and the other earns far less should generally allocate more of the limit to the higher-earning corporation, since an underused allocation on the smaller corporation provides no benefit. This needs to be revisited each year as income levels shift between the corporations.
What Association Does Not Do
Association affects the SBD limit. It does not merge the corporations for other purposes. Each associated corporation still files its own T2 return, maintains its own books, and is legally a separate entity with its own liabilities and its own bank accounts. Association is a tax-attribution rule, not a corporate law concept, and it does not create shared liability or combine the corporations’ financial statements.
Association also does not disqualify income from the SBD entirely the way personal services business (PSB) classification does. Personal Services Business Risk for Incorporated IT Contractors covers a separate and more severe problem: PSB income does not qualify for the SBD at all, associated or not. Association is about sharing a limit that still applies; PSB is about losing access to the limit altogether on the income in question.
Reviewing Before It Becomes a Filing Surprise
The association analysis should happen before a second corporation is incorporated, not at year-end when the T2 is being prepared and it becomes clear that two corporations under common control have each been claiming the full $500,000 limit independently. Retroactively fixing an unfiled or incorrect Schedule 23, and recalculating tax owing across multiple years for multiple corporations, is a considerably more expensive process than reviewing the structure upfront.
Anyone controlling, or planning to control, more than one corporation, whether an operating consultancy plus a holding corporation, multiple consulting entities, or a business corporation alongside a real estate or investment corporation, should have the association question reviewed as part of that structure’s setup, not discovered later.
Related Articles
- One Corporation or Multiple for a Consulting Firm? covers the broader structural decision for multi-owner consulting firms, including a shorter treatment of the associated corporation risk in that specific context.
- Holdco Structures for Growing IT Consulting Firms covers the Holdco structure in depth, including how association applies between an Opco and its Holdco.
- Personal Services Business Risk for Incorporated IT Contractors covers the separate risk of losing SBD eligibility entirely on income CRA reclassifies as PSB income.
Scope of This Article
This article covers the associated corporation rules as they apply to the small business deduction limit for IT consulting firms and consultants who control more than one corporation. It does not cover:
- The full technical text of section 256 or every deeming rule it contains
- Association rules as they apply to other tax attributes beyond the SBD limit, such as the capital gains exemption or refundable tax pools
- Provincial variations in how the SBD is calculated once the federal limit is allocated
- The mechanics of preparing or filing Schedule 23
The authoritative source is CRA’s guidance on associated corporations and section 256 of the Income Tax Act.
Get in touch if you control more than one corporation and want the association question reviewed before it affects a filing.