Most people picture the Tax Court of Canada as a forum for income-tax disputes. A large share of its docket, though, is GST/HST. The Excise Tax Act drives a different category of assessment — denied input tax credits, a clawed-back new-housing rebate, a backdated registration that converts years of revenue into uncollected tax — and those assessments come with procedural features that an income-tax appeal does not share. Knowing the differences before filing changes how the case is run.
Where a GST/HST appeal comes from
A GST/HST appeal begins the same way an income-tax appeal does: with an assessment, then a Notice of Objection, then either a reassessment that resolves the dispute or a confirmation that does not. If the Canada Revenue Agency confirms the assessment, or simply lets time run, the registrant can take the matter to the Tax Court of Canada. The Court is the same court that hears income-tax appeals, but the governing statute is the Excise Tax Act rather than the Income Tax Act, and a handful of rules diverge in ways that are easy to miss.
The objection itself is the gateway. A registrant has ninety days from the date of the GST/HST assessment to file a Notice of Objection. Miss that window and the right to object — and therefore the right to appeal — can be lost unless an extension of time is granted. For income-tax disputes, the practical advice we give on the notice of objection page applies equally here: file in time, frame the issues, and preserve the evidence.
The 180-day wait, and the collections difference
Two features set GST/HST apart at the front end. First, timing. For an income-tax matter, a taxpayer can take the file to the Tax Court once ninety days have passed since the objection was filed without a decision from an appeals officer. For GST/HST, the wait is one hundred and eighty days. The longer interval reflects the volume and complexity of GST/HST objections, but it also means a registrant who wants to escape a slow appeals queue waits twice as long before the Court becomes an option.
Second, and more consequential, collections. Filing an objection to an income-tax assessment generally pauses CRA collection of the disputed amount until the objection is resolved. GST/HST is a trust amount — tax the registrant collected from customers on the government's behalf — and the collections pause does not apply. The CRA can collect a disputed GST/HST assessment while the objection or appeal is still alive. A registrant facing a clearly wrong GST/HST assessment can spend a year or two watching the amount get collected before the file is corrected. For that reason, registrants with strong evidence sometimes skip the appeals officer and go straight to the Tax Court once the 180 days are up, simply to compress the timeline.
Input tax credit denials
The single most common GST/HST appeal is a denied input tax credit (ITC). A registrant claims credits for the GST/HST it paid on business inputs; the auditor disallows some or all of them; the assessment follows. ITC denials usually rest on one of a few grounds: the supporting documentation did not meet the prescribed information requirements, the expense was not for a commercial activity, the supplier was not in fact registered, or the claim fell outside the time limit.
The documentary requirements are unforgiving. The regulations specify the information an invoice must contain at different dollar thresholds — the supplier's name, the GST/HST registration number, the amount of tax, a description of the supply — and the absence of a required element can sink an otherwise legitimate claim. Many ITC appeals are won not on a point of law but on reconstructing the documentary record: obtaining duplicate invoices, confirming the supplier's registration status through the CRA's registry, and demonstrating that the inputs were used in commercial activity. A registration number that was valid at the time of the supply is provable years later, and that proof often resolves the file.
New-housing and new-residential-rental-property rebates
The GST/HST new-housing rebate, and its sibling the new-residential-rental-property rebate, generate a steady stream of appeals. The rebate returns a portion of the tax on a newly built or substantially renovated home, but it is hedged with conditions — the property has to be the primary place of residence of the claimant or a qualifying relation, the claim has to be filed within the statutory window, and the facts about occupancy and intention have to line up.
The recurring dispute is intention. A buyer purchases a pre-construction condominium intending to live in it, circumstances change before closing, and the unit is rented or sold instead. The CRA assesses to recover the rebate, treating the property as an investment rather than a residence. These appeals turn on contemporaneous evidence of intention at the relevant time — the original purchase agreement, financing arranged on an owner-occupied basis, a change in family or employment circumstances that explains the pivot. Where the facts support an honest change of plan, the rebate, or the rental-property version of it, can survive; where the pattern looks like an investor claiming an owner-occupier rebate, it usually does not.
Registration and the "you should have been collecting" assessment
A third category is the assessment that arises when the CRA decides a person should have been registered and collecting GST/HST and was not. A small business crosses the $30,000 small-supplier threshold without noticing, keeps invoicing without tax, and is later assessed for the tax it should have charged — often for several years — even though it never collected a cent of it from customers. The arithmetic is brutal: the business owes tax it cannot now go back and collect, plus interest and, sometimes, penalties.
Appeals in this category often focus on whether the threshold was actually crossed in the relevant period, whether the supplies were taxable at all (some are exempt or zero-rated), and whether the business can claim offsetting input tax credits for the tax it paid on its own inputs during the same period. The ITCs rarely erase the liability, but they reduce it, and a registrant under a backdated-registration assessment should always run the ITC analysis in parallel.
Procedure: informal and general
GST/HST appeals run through the same two procedural streams as income-tax appeals. The informal procedure is available where the amount of tax and penalties in dispute is within the prescribed limit; it has no filing fee, does not require a lawyer, and lets a corporation represent itself through an officer. The general procedure governs larger disputes — it has filing fees, defined and timed steps, examinations for discovery, and, for corporations, representation by a lawyer in almost all cases. We describe the mechanics in detail on the Tax Court appeal process page; the GST/HST version follows the same path.
One practical note on the informal procedure: because GST/HST assessments often bundle tax, interest, and penalties, the registrant should check whether the disputed amount, properly characterized, falls within the informal limit. Choosing the informal stream where it is available saves cost and time, and the decision still binds the parties on the issues actually decided.
Onus and evidence
In a GST/HST appeal, as in most tax appeals, the taxpayer carries the burden of proving the assessment wrong. The CRA's assessment is presumed correct, and the registrant has to dislodge it with evidence. The exception that reverses this onus — gross negligence penalties, where the Minister must prove the penalty was justified — applies to GST/HST penalties under the Excise Tax Act just as it does to the income-tax version, a point we take up on the gross negligence penalty defence page.
Because the taxpayer bears the onus on the underlying tax, the evidence is the case. For ITCs, that means the invoices and registration confirmations. For rebates, the occupancy and intention records. For backdated registrations, the revenue figures and the input-tax records. A GST/HST appeal is usually won in the document binder, not in legal argument.
Settlement
As with income-tax appeals, most GST/HST files that reach the Tax Court settle before trial. The Excise Tax Act, like the Income Tax Act, requires that any settlement be principled — grounded in a defensible view of the facts and the law, not a split-the-difference compromise. Where a registrant has a strong documentary case on most issues and a weak position on one, a principled settlement frequently has the CRA concede the strong issues. The discovery stage, where each side sees the other's evidence, is the usual moment this happens.
The takeaway
A GST/HST appeal looks like an income-tax appeal but runs on a different clock and a different collections regime. The 180-day wait, the absence of a collections pause on trust amounts, and the documentary intensity of ITC and rebate disputes all shape strategy from the first day. A registrant who understands those differences — and who builds the document record early — is in a far stronger position by the time the file reaches the Tax Court of Canada.