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ISC Register: What Ontario Corporations Need to Know About Shareholder Information Requirements

If you run an Ontario corporation, you need to keep an ISC Register. It's not optional, and the penalties for getting it wrong can be significant. Here's what you need to know.

By Frontier Law November 2025 3 min read
ISC Register: What Ontario Corporations Need to Know About Shareholder Information Requirements

If you own or manage an Ontario corporation, you need to be aware of the Individual with Significant Control (ISC) Register requirements. This regulation requires corporations to maintain detailed records of individuals who have significant control over the company.

What is the ISC Register?

The ISC Register is a record that every private Ontario corporation must maintain. It contains information about individuals who have significant control over the corporation—typically those who own or control a significant number of shares or who have significant influence over the corporation.

Who Needs to Comply?

All private corporations incorporated under the Ontario Business Corporations Act (OBCA) must maintain an ISC Register. This includes:

  • Small businesses
  • Family-owned corporations
  • Professional corporations
  • Holding companies

Publicly traded companies are exempt from this requirement.

What Information Must Be Recorded?

For each individual with significant control, the register must include:

  • Full legal name
  • Date of birth
  • Residential address
  • Jurisdiction of residence for tax purposes
  • Date the individual became or ceased to be an individual with significant control
  • Description of how the individual has significant control
  • Any other prescribed information

What Constitutes “Significant Control”?

An individual has significant control if they:

  • Own 25% or more of the corporation’s voting shares
  • Own 25% or more of all shares measured by fair market value
  • Have direct or indirect influence that, if exercised, would result in control of the corporation
  • Have any combination of the above

Penalties for Non-Compliance

Failure to maintain an ISC Register or provide accurate information can result in:

  • Fines for the corporation
  • Personal liability for directors
  • Potential criminal charges for knowingly providing false information

Steps to Ensure Compliance

1. Identify Individuals with Significant Control

Review your corporate structure to identify all individuals who meet the criteria.

2. Gather Required Information

Collect all necessary information from identified individuals.

3. Create and Maintain the Register

Establish a proper ISC Register and keep it with your corporate records.

4. Update Regularly

The register must be updated whenever there are changes to the individuals with significant control or their information.

5. Annual Review

Conduct an annual review to ensure all information remains accurate and current.

How Frontier Law Can Help

Maintaining compliance with ISC Register requirements is an ongoing obligation. Our corporate law team can help you:

  • Determine who qualifies as having significant control
  • Set up your ISC Register properly
  • Integrate ISC Register maintenance into your annual corporate procedures
  • Update your minute books to reflect compliance

Don’t risk penalties for non-compliance. Contact us to discuss your corporation’s ISC Register requirements.


This article is for informational purposes only and does not constitute legal advice. For advice specific to your situation, please contact us for a consultation.

Topics: corporate law Ontario corporations ISC register compliance shareholder information

Disclaimer: This article is for informational purposes only and does not constitute legal advice. For advice specific to your situation, please contact us for a consultation.

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