GST/HST Audits, Objections and Appeals

The GST/HST system looks simple from a distance: a business charges tax on what it sells, claims back the tax it pays on its inputs, and remits the difference. In practice, almost every line of that calculation can be questioned on audit. The Canada Revenue Agency administers the goods and services tax and harmonized sales tax under the Excise Tax Act, and a GST/HST audit examines whether you charged tax when you should have, whether your supplies were properly characterized, and whether the input tax credits you claimed are actually supported. A reassessment can reach back years and can survive even while you dispute it, because the tax at issue is treated as money you held in trust for the Crown rather than your own.

This page explains how GST/HST audits work, the issues that most often drive a reassessment, the strict deadlines for objecting and appealing under the Excise Tax Act, the four-year reassessment limit and its exceptions, and why an objection usually does not stop the CRA from collecting. It is general information about Canadian federal tax law, not legal advice for your particular situation.

How a GST/HST audit works and where it focuses

A registrant's core GST/HST obligation is to account for net tax for each reporting period: broadly, the tax collected or collectible on taxable supplies, reduced by the input tax credits (ITCs) the registrant is entitled to claim on its own purchases. The Excise Tax Act requires registrants to keep books and records sufficient to determine their liabilities and entitlements, and the CRA's audit powers let it inspect those records, request documents and information, and assess on the basis of what it finds. When the numbers a registrant reported do not line up with the supporting documentation, an audit becomes a reassessment.

Most GST/HST audits gravitate toward a familiar set of issues:

• Input tax credits. The CRA frequently denies ITCs where the supporting documentation does not meet the prescribed requirements, where the expense is not sufficiently connected to commercial activity, or where the registration number of the supplier cannot be verified. Documentary defects alone can cost a business credits it was otherwise entitled to.
• Exempt versus taxable supplies. The Act distinguishes among taxable supplies (which carry GST/HST), zero-rated supplies (taxable at 0%), and exempt supplies (which carry no tax but also generally yield no ITCs). Misclassifying a supply — treating something as exempt or zero-rated when the CRA views it as taxable — is a recurring source of reassessment, particularly in sectors such as health care, financial services, education and residential rent where the lines are genuinely difficult.
• Real property. Transactions involving land and buildings are among the most technically demanding in the entire GST/HST system, with special rules for the sale of new housing, the self-supply of residential complexes, change-of-use, and the way tax is accounted for on many real property sales. The dollar amounts are large and the rules are unforgiving, which makes real property a frequent audit target.

Each of these issues turns on the precise facts and the precise wording of the Act, and each is contestable. An auditor's initial position is a starting point, not a verdict.

Input tax credits and the documentation problem

Input tax credit disputes are the bread and butter of GST/HST audits. The general entitlement to an ITC arises where a registrant acquires property or services for consumption, use or supply in the course of its commercial activities, but the entitlement is conditioned on holding sufficient documentary evidence before the credit is claimed. The Excise Tax Act and its regulations set out specific information that supporting documents must contain, and those requirements scale with the dollar value of the purchase — larger invoices must show more, including the supplier's GST/HST registration number and, at the highest tier, the recipient's name and the terms of the supply.

The practical consequence is that a business can be fully entitled to a credit in substance and still have it denied because an invoice is missing a required element or a supplier's registration number does not check out. Other common ITC battlegrounds include credits claimed on costs the CRA characterizes as personal rather than commercial, credits on passenger vehicles and meals and entertainment that are subject to restrictions, and timing questions about the reporting period in which a credit was properly claimable. Because these denials are often about evidence and characterization rather than honest entitlement, they are frequently reduced or reversed once the record is properly assembled and the legal test is applied to the facts. We address this in more depth under input tax credit denials.

Exempt, zero-rated and taxable supplies

Whether a supply is taxable, zero-rated or exempt determines both the tax you must charge and the credits you can claim, and getting the characterization wrong cuts both ways. If the CRA decides that supplies you treated as exempt were in fact taxable, it will assess the tax you should have charged — often without any ability for you to go back and collect it from your customers after the fact. If it decides supplies were exempt rather than taxable, it may deny the ITCs you claimed on the inputs used to make them.

The hardest cases cluster in areas the Act treats specially. Financial services are generally exempt but the boundary of what counts as a financial service is notoriously litigated. Health care, residential rent, and certain educational and child-care services have their own exemption rules with detailed conditions. Zero-rated categories, including many exports and basic groceries, carry their own definitional traps. Because the classification of a single recurring supply can drive years of liability, this is an area where careful legal analysis of the actual supply — what is really being provided, to whom, and on what terms — matters enormously.

GST/HST and real property

Real property deserves separate treatment because the rules are distinct and the exposure is large. The sale of newly constructed or substantially renovated residential housing is generally taxable, while the sale of used residential housing is generally exempt, and the line between “new” and “used” is itself a question that has produced significant disputes. Builders face special self-supply rules that can deem a sale to have occurred — and tax to be payable — when a residential complex is first rented out, even though no third-party sale has taken place. Change-of-use rules can trigger GST/HST when property moves between commercial and residential use.

Many taxable sales of real property are also subject to special accounting rules that shift the obligation to self-assess and remit onto the purchaser in defined circumstances, which is a frequent source of error and reassessment for both sides of a transaction. New housing and rental rebates add a further layer, and rebate claims are themselves regularly audited and denied. These issues overlap heavily with our work on GST/HST on real estate, and registration questions that arise when a person becomes liable to charge tax are addressed under GST/HST registration and compliance.

The notice of (re)assessment and the four-year limit

A GST/HST audit concludes with an assessment or reassessment of net tax, interest and, in some cases, penalties. The Excise Tax Act generally requires the Minister to assess net tax within four years after the later of the day the return for the reporting period was filed and the day it was required to be filed. Once that period passes, the reporting period is, in broad terms, closed, and the CRA cannot freely reassess it.

As with income tax, this limit is a genuine protection but not an absolute one. Section 298 of the Excise Tax Act sets out exceptions that allow the Minister to assess beyond the four-year period. The most important are where the person has made a misrepresentation attributable to neglect, carelessness or wilful default, or has committed fraud in making or filing a return or in supplying information under the Act, and where the person has filed a waiver within the four-year period. There are also longer or special periods for certain matters, such as penalties in particular circumstances. The structure mirrors the income tax rules, and the same threshold question often arises: can the CRA actually bring itself within an exception, or is it trying to reopen a period that should be closed? Where the CRA reaches past the normal window, the burden of justifying that reach generally rests on the Minister, an issue we explore under statute-barred reassessments.

A waiver request near the end of an audit deserves the same caution in the GST/HST context as it does for income tax. Signing one extends the time the CRA has to reassess the specified matters and surrenders a defence you would otherwise hold, so the scope and timing of any waiver should be reviewed before it is signed.

Objecting under section 301 of the Excise Tax Act

If you disagree with a GST/HST assessment or reassessment, the first formal step is to file a Notice of Objection under section 301 of the Excise Tax Act. The deadline is strict: the objection must generally be filed within 90 days after the day the notice of assessment was sent. A valid objection sends the matter to the CRA's appeals area, which reviews the assessment independently of the auditor and can confirm it, vary it, or reassess.

The objection stage is the point at which the legal and factual arguments are first set out in full, and it matters more than many registrants realize. Properly framing the dispute — identifying every issue, marshalling the documentation, and stating the grounds and the relief sought — shapes everything that follows, because issues left out at this stage can be difficult to raise later. If the 90-day deadline is missed, the Act allows an application for an extension of time in limited circumstances, generally within a further year and subject to conditions, but the safe course is always to object within the original period. The objection process is the same backbone that runs through our broader tax disputes and objections practice.

Appealing to the Tax Court of Canada

If the objection does not resolve the matter, the dispute moves to the Tax Court of Canada. Under sections 302 and 306 of the Excise Tax Act, a person who has objected may appeal to the Tax Court after the Minister confirms or reassesses in response to the objection, or once 180 days have passed since the objection was filed without the Minister having dealt with it. The general deadline to file an appeal after the CRA confirms or reassesses is 90 days from that decision.

The Tax Court hears GST/HST appeals under both its informal procedure, which is faster and less formal and is available below a monetary threshold, and its general procedure for larger or more complex matters. The Court is where the characterization of supplies, the entitlement to input tax credits, and the validity of a reassessment are ultimately decided on the evidence and the law. Many disputes are resolved by negotiated settlement before a hearing, but the existence of a credible appeal frequently shapes those discussions. Our work at this stage is described further under Tax Court of Canada appeals.

Why an objection usually does not stop collection

This is the feature of GST/HST disputes that surprises business owners most, and it can be financially decisive. For ordinary income tax, filing a valid objection generally restricts the CRA from collecting the disputed amount until the dispute is resolved. GST/HST is different. The tax you collect from your customers is treated as money held in trust for the Crown — it was never your money to begin with — and the Excise Tax Act reflects this in its collection rules.

The practical result is that an objection or appeal does not automatically pause collection of an assessed GST/HST debt the way it does for income tax. The CRA can continue to pursue payment of disputed net tax through requirements to pay, bank holds and its other collection tools even while the matter is under objection or before the Tax Court. This trust-fund character is also why unremitted GST/HST can be assessed personally against the directors of a corporation, a risk addressed under directors' liability, and why managing the collection side of a GST/HST dispute is often as important as the dispute itself. In practice this can mean pursuing a payment arrangement or other protective steps in parallel with the objection or appeal, rather than assuming the debt is on hold.

Penalties, interest and related exposure

A GST/HST reassessment usually carries interest on the unremitted net tax, and it can carry penalties. Where the CRA alleges that a person knowingly, or under circumstances amounting to gross negligence, made a false statement or omission, it may assess a penalty on that basis, which raises a heightened standard the Minister must establish. Failure-to-file and related administrative penalties can also apply. These overlap with our work on gross negligence penalties, and where past returns were never filed or tax was never reported, a registrant may want to consider whether a voluntary disclosure is available before the CRA initiates contact, since coming forward proactively can change the penalty and prosecution picture. Because penalties, interest and the underlying tax are assessed together, the response usually has to address all of them at once.

How Barrett Tax Law approaches this

Our tax lawyers begin a GST/HST matter by understanding exactly what the CRA has assessed and why. We review the auditor's working papers and the basis for each adjustment, separate the issues that turn on documentation from those that turn on the characterization of supplies, and test whether the reassessment falls within the four-year period under the Excise Tax Act or depends on an exception the Minister must justify. From there we develop the response: assembling the records needed to support denied input tax credits, building the legal argument on exempt, zero-rated and taxable supplies and on real property, and preserving rights through a timely Notice of Objection under section 301 and, if necessary, an appeal to the Tax Court of Canada under sections 302 and 306.

Because GST/HST is a trust amount and an objection does not stop collection on its own, we also pay close attention to the collection side from the outset, so that a business is not caught between disputing an assessment and facing enforcement on the very same amount. We act for registrants across many sectors, and every situation turns on its own facts, so nothing on this page is a substitute for advice on your circumstances. If you have received a GST/HST audit query, a proposal letter, or a notice of assessment or reassessment, you are welcome to reach out for a free, confidential consultation to discuss your options and the next steps that make sense for you.