- The ISC register is a corporate record — required for private (non-publicly traded) OBCA corporations — that identifies the individuals who ultimately own or control the corporation,…
- An individual generally has significant control over a corporation if they: - Own, control, or direct a significant share of the corporation's outstanding voting shares or shares by…
- You need to review and, where necessary, update your ISC register whenever a change occurs in who has significant control, including:
If your Ontario corporation has changed hands even slightly — a new shareholder brought in, an existing shareholder's stake grown or sold down, a founder's shares moved into a family trust — you likely have a legal obligation sitting quietly in your minute book that most owners never think about until it comes up in a financing or sale: your individuals with significant control (ISC) register.
Private Ontario corporations under the Business Corporations Act (OBCA) are required to maintain this transparency register, and it is not a "set it once at incorporation" document. Ownership and control changes are exactly what trigger the obligation to update it.
What the ISC Register Is, and Why It Exists
The ISC register is a corporate record — required for private (non-publicly traded) OBCA corporations — that identifies the individuals who ultimately own or control the corporation, even where that control sits behind holding companies, trusts, or joint arrangements. It exists to make it harder to obscure who really stands behind a corporation, for purposes ranging from anti-money-laundering policy to basic corporate transparency.
Corporations whose shares are listed on a designated stock exchange are generally exempt, since public trading and disclosure rules already provide that transparency. Almost every ordinary small or mid-sized private Ontario corporation is not exempt.
What Counts as "Significant Control"
An individual generally has significant control over a corporation if they:
- Own, control, or direct a significant share of the corporation's outstanding voting shares or shares by value — assessed against a percentage threshold set out in the Act — either alone or jointly with others; or
- Have direct or indirect influence that, if exercised, would result in control in fact of the corporation, whether or not they hold any shares at all; or
- Are part of a group of individuals who together meet either of the above through an agreement or arrangement to act jointly.
This means a shareholder with a modest individual stake can still count as an individual with significant control if they act jointly with others under a shareholders' agreement or informal arrangement that together crosses the threshold. The exact percentage threshold and other qualifying tests are technical — confirm the current definition with your corporate lawyer rather than assuming a round number.
What Triggers an Update
You need to review and, where necessary, update your ISC register whenever a change occurs in who has significant control, including:
| Trigger event | Why it matters |
|---|---|
| A new investor or partner acquires shares | May newly cross the significant-control threshold |
| An existing shareholder increases their holding | May newly cross the threshold even without a change in ownership structure |
| A shareholder sells or transfers shares, including to a family member or trust | May remove that individual and/or add a new one |
| Shares move into or out of a holding company | The register looks through to the ultimate individual, not just the immediate corporate shareholder |
| A shareholders' agreement changes who acts jointly with whom | Can change who is treated as part of a control group |
| A significant control holder's personal information changes (address, name) | The register's identifying information needs to stay current |
What Information Must Be Recorded
For each individual with significant control, the register generally needs to capture their full legal name, date of birth, latest known address, jurisdiction(s) of residence for tax purposes, the date they became (and, later, ceased to be) an individual with significant control, and a description of how their significant control is held or exercised.
How Quickly You Need to Update It
The OBCA requires the register to be kept current, not updated at your convenience — the corporation is expected to update it promptly after it becomes aware of a change, rather than treating it as an annual housekeeping task. The exact prescribed timeline for making the update can be technical; confirm the current requirement with your corporate lawyer rather than guessing at a specific number of days, since getting this wrong can itself be a compliance gap.
Frequently asked questions
Do I need an ISC register if my corporation only has one or two shareholders?
Yes. Corporation size does not exempt you — the obligation applies to private OBCA corporations generally, and a closely held corporation with one or two shareholders almost always has at least one individual with significant control to record.
What if I incorporated federally instead of under the OBCA?
Federal (CBCA) corporations have their own similar transparency register requirement, with some separate rules of its own, including registry-filing obligations that differ from Ontario's. Confirm the current requirements that apply specifically to a federally incorporated business.
Does a holding company owning my shares mean I don't need to list myself personally?
No — the register is designed to look through intermediate corporate holding structures to the actual individual who ultimately controls or benefits from the shares. Hiding behind a holding company does not remove the obligation to identify the individual behind it.
What if I'm not sure whether a recent change actually crosses the significant-control threshold?
This is exactly the kind of judgment call worth getting reviewed rather than guessing on your own, since the threshold accounts for joint arrangements and control in fact, not just simple share percentages.
This is a corporate question
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