ARTICLE
28 November 2025

Tax Mistakes: Fixing Errors With The Canada Revenue Agency And Revenu Québec

MT
Miller Thomson LLP

Contributor

Miller Thomson LLP (“Miller Thomson”) is a national business law firm with approximately 500 lawyers across 5 provinces in Canada. The firm offers a full range of services in litigation and disputes, and provides business law expertise in mergers and acquisitions, corporate finance and securities, financial services, tax, restructuring and insolvency, trade, real estate, labour and employment as well as a host of other specialty areas. Clients rely on Miller Thomson lawyers to provide practical advice and exceptional value. Miller Thomson offices are located in Vancouver, Calgary, Edmonton, Regina, Saskatoon, London, Waterloo Region, Toronto, Vaughan and Montréal. For more information, visit millerthomson.com. Follow us on X and LinkedIn to read our insights on the latest legal and business developments.
The Canadian and Quebec tax systems are founded on a complex web of concepts and rules. This can make preparing a tax return quite challenging, and it is not unusual...
Canada Tax
Marie-Hélène Tremblay’s articles from Miller Thomson LLP are most popular:
  • within Tax topic(s)
  • with Senior Company Executives, HR and Finance and Tax Executives
  • in United States
  • with readers working within the Accounting & Consultancy, Technology and Property industries

*This is a modified version of an article originally published in Finance et Investissement.

The Canadian and Quebec tax systems are founded on a complex web of concepts and rules. This can make preparing a tax return quite challenging, and it is not unusual for tax specialists to find mistakes in their clients' files. While some of these are minor and have no serious repercussions, others can result in substantial tax adjustments. Fortunately, the tax authorities provide various ways for taxpayers to fix a mistake.

What is the voluntary disclosure program?

Both the Canada Revenue Agency and Revenu Québec have a voluntary disclosure program allowing taxpayers to correct a tax error or omission. These programs are strictly regulated and have several eligibility conditions that limit the situations in which they can be used. This makes it imperative to carefully analyze their respective rules, which differ in several respects.

Taxpayers can also anonymously contact a representative of either tax authority for clarification before submitting an official application. Generally speaking, for an application to be accepted, it must:

  • be voluntarily presented by the taxpayer;
  • include information related to a tax year that is at least one year past the filing due date;
  • include errors or omissions with applicable interest charges and penalties;
  • include all the application's supporting documents as required by the relevant tax authorities;
  • be accompanied by a payment or a request for a payment arrangement on the estimated amount of tax payable.

Once an application has been accepted, the charges are still payable in full and penalties will generally not be applied. The interest payable may also be reduced, depending on the type of case and the tax authority concerned.

Good to know: With some exceptions, a voluntary disclosure application may be submitted only once.

Can you simply amend a tax return?

Yes. When an error is small or has minimal financial impact, it is often simpler to correct it by filing an amended return. This simpler and less costly option allows you to regularize your situation without going through the entire voluntary disclosure process, which is often cumbersome and requires a considerable investment of time and money.

However, filing an amended return does not lead to reduced penalties or interest, and the tax authorities are not obliged to process it, so it is only accepted at their discretion.

What if the error was discovered during a tax audit?

Sometimes a taxpayer finds an inaccuracy while preparing the documents requested by the authorities during a tax audit. In such cases, it is often better to report the error to the designated auditor right away. Being transparent in this way can lead to a fairer settlement and reduce the risk of additional penalties.

In conclusion: Correct it, but be methodical

Whether you are making a voluntary disclosure, filing an amended return or making a correction during an audit, it is crucial to adopt a structured and well-documented approach. The financial and legal consequences can be considerable, so it is strongly recommended to consult an experienced tax specialist to get the right advice and the best settlement of your case.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

Mondaq uses cookies on this website. By using our website you agree to our use of cookies as set out in our Privacy Policy.

Learn More