Objecting to a GST/HST Assessment in Canada: Who Handles It

You have opened a GST/HST notice of assessment and the numbers are not what you expected. Before deciding what to do, most business owners want to know three things: where an objection goes, who actually looks at it, and how long they have.

This article walks through those points in plain language. GST/HST objections follow their own rules under the Excise Tax Act, and they differ in important ways from income tax objections, so it helps not to mix the two.

This article covers Canadian federal tax law, which applies in every province.

The deadline: 90 days from the notice date

Under the Excise Tax Act, a GST/HST objection must be filed within 90 days after the day the notice of assessment is sent. CRA's own page gives the same 90-day deadline measured from the notice date.

The 90 days run from the day the notice of assessment was sent. If your mail was delayed, the 90 days may already be running, so check the date printed on the notice first.

The objection must be on the prescribed form and set out the reasons and all relevant facts. The Minister may accept an objection that was not filed in the prescribed manner, but you should not count on that.

Where the objection goes

CRA says to file with Form GST159 by mail or fax to the Chief of Appeals at the Appeals Intake Centre in Sudbury, or online through My Business Account by choosing "Register my formal dispute". Online objections go directly to the Appeals Division for validation and review.

If you use an accountant or other representative, they can file through Represent a Client.

Quebec works differently. Revenu Québec generally administers GST/HST in Quebec, while the CRA administers it for selected listed financial institutions there. If your business is in Quebec, confirm which agency issued your assessment before you file.

Who reviews it

Objections are reviewed by CRA's Appeals Division, and online objections go directly to it for validation and review. It is a review inside the CRA, not a court hearing.

If you held back information during the audit and only supply it with your objection, the file may be sent back for a second review. That is a reason to give the full picture as early as you can.

Review times vary. For GST/HST objections resolved in August 2026, the average was 148 days for low complexity and 388 days for medium complexity, such as new housing rebates and input tax credits, while high complexity was over 500 days. These are monthly averages and change, so treat them as a rough guide only.

Paying, interest and collection while you wait

The CRA says it can keep collecting amounts you owe while a GST/HST objection is pending, unlike income tax. Interest still applies, and you can pay all or part of the disputed amount to limit it.

This matters if you have heard that collection stops during an objection. That is the income tax rule, and it does not carry over to GST/HST as CRA describes it. A lawyer or accountant can help you plan cash flow before you file.

If you disagree with the result, or you are late

You can appeal to the Tax Court of Canada once the Minister has confirmed or reassessed, or 180 days after the objection was filed if there is no decision. The appeal cannot be started more than 90 days after the day the Minister sends the notice of confirmation or reassessment.

Do not confuse this with income tax, where the wait before appealing for lack of a decision is 90 days.

If you miss the objection deadline, the Excise Tax Act allows an application to the Minister within one year after the deadline. You must show you were unable to act or had a genuine intention to object, that an extension is just and equitable, and that you applied as soon as circumstances allowed. The application goes to the Chief of Appeals with a copy of the objection.

Some larger filers have extra requirements. GST/HST "specified persons", meaning listed financial institutions and non-charities with threshold amounts over $6 million in both the current and previous fiscal year, must describe each issue, state the relief sought and give facts and reasons, with 60 days to cure missing information.

What to do next

• Find the date the notice of assessment was sent and count 90 days forward.
• Confirm whether the CRA or Revenu Québec issued the assessment.
• Gather the invoices, returns and records that support your position.
• Decide whether to file online through My Business Account or on Form GST159.
• Consider paying all or part of the disputed amount to limit interest.
• Speak with a lawyer or accountant if the amount is large or your business is in a special category.

Frequently asked questions