Notice of Objection (T400A): Deadlines, Steps and What Happens Next

Disagree With a CRA Assessment or Reassessment?

If you disagree with an assessment or reassessment issued by the Canada Revenue Agency (CRA), you may have the right to file a formal Notice of Objection.

A Notice of Objection begins the CRA’s administrative dispute process and gives you an opportunity to challenge the assessment before potentially proceeding to the Tax Court of Canada.

Strict deadlines apply. This guide explains when an objection must be filed, how Form T400A works, what information an objection should contain, what happens during the CRA Appeals process, and what options may be available if the deadline has already passed.

For legal representation in a tax dispute, visit our CRA tax objection lawyers page.

Quick Answer: What Should You Do First?

Check the date on your assessment or reassessment: the objection deadline depends on the taxpayer and type of assessment.
Identify what you are disputing: determine the tax years, amounts, adjustments, penalties, or other issues you disagree with.
Gather supporting evidence: collect the documents and facts that support your position.
Choose how to file: an objection may generally be filed electronically through CRA online services or in writing, including by using Form T400A where applicable.
Do not wait until the deadline: preparing the factual and legal basis of an objection can take time.
If the deadline has passed: determine immediately whether an extension of time to object is still available.

What Is a CRA Notice of Objection?

A Notice of Objection is the formal process used to dispute certain CRA assessments or determinations.

For an objection under the Income Tax Act, the taxpayer explains why the assessment or determination is incorrect and provides the relevant facts and supporting documentation.

After an objection is filed, the matter is reviewed through the CRA Appeals process. The appeals officer may request additional information and will review the assessment and the taxpayer’s position before a decision is made.

The CRA may ultimately:

Confirm the assessment;
Vary the assessment;
Vacate the assessment; or
Issue a reassessment or redetermination reflecting the outcome of the review.

For official CRA guidance, see P148 – Resolving Your Dispute: Objection Rights Under the Income Tax Act.

When Should You File a Notice of Objection?

A Notice of Objection may be appropriate when you disagree with the legal or factual basis of an assessment or reassessment.

Common disputes can involve:

Unreported or allegedly unreported income;
Denied business expenses;
Gross-negligence penalties;
Capital gains versus business income treatment;
Real estate transactions;
Shareholder benefits;
Corporate income tax adjustments;
Tax credits or deductions;
Foreign income or reporting issues; or
Other adjustments made following a CRA audit or review.

If the assessment resulted from an audit, you may also find our CRA Audit Letter: What to Do Next guide helpful for understanding how the dispute may have developed.

What Is the Deadline to File a Notice of Objection?

The deadline depends on the taxpayer and the type of assessment or determination.

Individuals and Graduated Rate Estates

For an individual other than a trust, or for a graduated rate estate for the year, the deadline is generally the later of:

One year after the filing due date for the return; or
90 days after the date of the notice of assessment or determination.

Different rules can apply to certain matters, including loss determinations and some assessments involving over-contributions to registered plans.

Corporations

Corporations generally have 90 days from the date of the notice of assessment or determination to file an objection.

Trusts and Other Cases

In other cases, including many trust assessments and certain determinations, the objection period is generally 90 days.

Because the applicable deadline can depend on the legislation and type of assessment, the notice should be reviewed carefully as soon as it is received.

What Is Form T400A?

Form T400A – Notice of Objection (Income Tax Act) is the CRA form that can be used to file an objection to a Notice of Assessment or Notice of Determination issued under the Income Tax Act.

Using Form T400A is one method of filing an objection, but it is not necessarily the only method.

Depending on the taxpayer and circumstances, an objection may also be filed through applicable CRA online services or by sending a written Notice of Objection containing the required information.

You can access the current CRA form here: T400A – Notice of Objection (Income Tax Act).

How to File a CRA Notice of Objection

Option 1: File Electronically

Eligible taxpayers and authorized representatives may be able to submit an objection through the CRA’s online services.

The electronic filing process allows the taxpayer or representative to identify the assessment being disputed, provide the reasons for the objection, and submit supporting information.

CRA online filing options and terminology may change over time, so taxpayers should follow the current instructions available through their CRA account.

Option 2: File Form T400A or a Written Objection

A taxpayer may also submit an objection in writing in accordance with CRA requirements.

The objection should clearly identify:

The taxpayer;
The assessment or determination being disputed;
The applicable taxation year or reporting period;
The reasons for the objection;
The relevant facts;
The changes or relief being requested; and
Relevant supporting documents.

When filing by mail, keep a complete copy of the objection and proof showing when and how it was sent.

What Should a Strong Notice of Objection Include?

A Notice of Objection should do more than simply state that the taxpayer disagrees with the CRA.

A well-prepared objection generally identifies each disputed issue and explains the taxpayer’s factual and legal position.

Depending on the case, supporting material may include:

Contracts and agreements;
Receipts and invoices;
Bank and credit-card records;
Accounting records;
Corporate documents;
Real estate transaction documents;
Correspondence with the CRA;
Evidence addressing assumptions made during an audit;
Legal authorities; and
Other records relevant to the disputed assessment.

The objective is to make clear what the CRA assessed, why the taxpayer says the assessment is incorrect, and what result the taxpayer is seeking.

Special Rules for Large Corporations

Large corporations are subject to additional requirements when filing an objection under the Income Tax Act.

A large corporation’s objection generally must:

Reasonably describe each issue;
Specify the relief sought for each issue; and
Provide the facts and reasons relied upon for each issue.

These requirements can have important consequences for the issues that may later be pursued in litigation.

Large corporations may also be required to pay 50% of the amount in dispute while the objection or appeal is outstanding.

What Happens After You File a Notice of Objection?

Once the CRA receives the objection, the dispute proceeds through the CRA Appeals process.

An appeals officer may:

Review the assessment and audit working papers;
Review the Notice of Objection and supporting evidence;
Request further information or documents;
Discuss disputed issues with the taxpayer or representative; and
Consider factual and legal submissions.

After completing the review, the CRA may confirm the assessment or make changes that result in a reassessment or redetermination.

Can the CRA Collect the Tax While an Objection Is Pending?

It depends on the type of tax debt.

For many disputed amounts assessed under the Income Tax Act, the CRA is generally subject to collection restrictions while the objection process is underway.

However, important exceptions apply.

For example, collection action may continue in relation to certain amounts that were required to be withheld or remitted. Different collection rules also apply to GST/HST liabilities, and large corporations can be required to pay 50% of disputed income-tax amounts.

The CRA may also apply certain amounts otherwise payable to the taxpayer against an outstanding debt even while an objection or appeal is ongoing.

For official information, see the CRA’s Tax Collections Policies.

If you are already facing enforcement action, learn more about our CRA collections and tax debt services.

What If You Miss the Notice of Objection Deadline?

Missing the ordinary objection deadline does not always end the dispute, but additional strict deadlines apply.

Under the Income Tax Act, a taxpayer may apply to the CRA for an extension of time to object.

The application generally must be made within one year after the original objection deadline expired.

The taxpayer must also satisfy the applicable statutory requirements. These include demonstrating that:

Within the original objection period, the taxpayer was unable to act or instruct someone to act on their behalf, or had a bona fide intention to object;
It would be just and equitable to grant the application; and
The application was made as soon as circumstances permitted.

An application for an extension should include the proposed Notice of Objection and an explanation of why the original deadline was missed.

What If the CRA Refuses the Extension?

If the CRA refuses an application for an extension of time to object, the taxpayer may be able to apply to the Tax Court of Canada to have the extension granted.

An application may also be available where the CRA has not notified the taxpayer of its decision within 90 days after the extension application was made.

If the CRA refuses the extension, the Tax Court application generally must be filed within 90 days after the CRA sends notice of its refusal.

What Happens If the CRA Confirms the Assessment?

If the taxpayer disagrees with the CRA’s decision on the objection, the next step may be an appeal to the Tax Court of Canada.

A Notice of Appeal generally must be received by the Tax Court within 90 days after the CRA sends its decision on the objection.

Under the Income Tax Act, a taxpayer may also generally appeal to the Tax Court if the CRA has not notified the taxpayer of its decision within 90 days after the objection was filed.

Learn more about our Tax Court appeal services.

Can Penalties and Interest Be Addressed Through a Notice of Objection?

Whether an objection or a taxpayer relief request is appropriate depends on what is being challenged.

If the taxpayer says a penalty or interest amount was assessed incorrectly under the law, that issue may form part of an objection where objection rights exist.

By contrast, a request asking the CRA to exercise discretion to cancel or waive eligible penalties or interest because of circumstances such as extraordinary events, CRA delay, or financial hardship is generally made through the taxpayer relief process.

Learn more about our CRA penalty and interest relief services.

How Our Tax Lawyers Assist With CRA Objections

Determine the applicable objection deadline;
Review the assessment, reassessment, audit findings, and CRA correspondence;
Identify the factual and legal issues in dispute;
Prepare the Notice of Objection and supporting submissions;
Organize documentary evidence;
Communicate with CRA Appeals as an authorized representative;
Respond to additional information requests;
Advise on collection exposure while the objection is pending;
Prepare extension-of-time applications where available; and
Advise on a Tax Court appeal if the dispute is not resolved.

Frequently Asked Questions About CRA Notices of Objection

Do I have to use Form T400A to file an objection?

No. Form T400A is one method of filing an Income Tax Act objection. Depending on the circumstances, taxpayers may also be able to file electronically through CRA online services or submit a written objection containing the required information.

What is the deadline to file a Notice of Objection?

For an individual other than a trust, or a graduated rate estate for the year, the deadline is generally the later of one year after the filing due date or 90 days after the date of the notice of assessment or determination. Corporations generally have 90 days. Different rules may apply to certain assessments and determinations.

What happens if I file my objection late?

You may be able to apply for an extension of time to object, but the application generally must be filed within one year after the original objection deadline and the statutory conditions for an extension must be satisfied.

Will the CRA stop collections while I object?

Collection restrictions generally apply to many disputed income-tax amounts, but there are important exceptions. GST/HST, source deductions, large-corporation assessments, jeopardy situations, and other categories may be treated differently.

How long does the CRA objection process take?

There is no single timeline for every objection. Processing time depends on factors such as the complexity of the issues, the amount of evidence involved, the type of objection, and whether additional information is required.

Can I appeal if the CRA rejects my objection?

Yes. If the CRA confirms the assessment or issues a reassessment following the objection and you continue to disagree, you may have the right to appeal to the Tax Court of Canada. A 90-day appeal deadline generally applies.

Do I need a tax lawyer to file a Notice of Objection?

Legal representation is not mandatory. However, a tax lawyer can be particularly useful where the amounts are significant, the issues are legally complex, penalties have been imposed, an audit involved disputed assumptions, or the matter may eventually proceed to the Tax Court of Canada.

Speak With a Tax Lawyer About a Notice of Objection

If you disagree with a CRA assessment or reassessment, it is important to identify the applicable objection deadline and determine the strongest factual and legal basis for the dispute.

KR Law Firm represents individuals and businesses in CRA objections and related tax disputes across Canada.

Book a Free Consultation with one of our tax lawyers to discuss your CRA assessment, objection deadline, or ongoing tax dispute.