HST/GST AUDIT ADVISORY · 02
HST/GST Audit & Exposure Advisory
Advisory for denied input tax credits, real estate HST, documentation gaps, cash sales and deposits, and the multi-year exposure that builds quietly across GST/HST reporting periods — before CRA raises it, and after.
The short answer
HST/GST exposure compounds in a way income tax rarely does: one recurring flaw — a missing supplier registration number, an unreconciled cash deposit, an assignment sale treated as tax-free — repeats across every reporting period until CRA raises it in a single assessment. I advise Canadian business owners, real estate groups, and cash-intensive businesses through HST/GST audits, denied input tax credits, and assessments — and before that point, on quantifying and correcting exposure while options such as the Voluntary Disclosures Program remain open. The approach is factual and discreet: establish what the documentation actually supports, measure the exposure period by period, and deal with CRA deliberately, in the right order.
“In an HST/GST audit, the question is rarely whether tax was charged — it is whether the paper behind every credit claimed can stand on its own, period after period.”
HST/GST Exposure Can Grow Quickly
GST/HST is unlike most tax risk an owner carries. The amounts collected from customers are held in trust for the Crown, each reporting period stands as its own assessment, and CRA's collections powers for assessed amounts are among the most direct it has — including garnishment of up to 50% of wages or 100% of contractor receivables without a court order. A GST/HST problem is rarely a polite problem, and it is almost never a single-period problem.
The growth mechanism is repetition. A missing supplier registration number, a misclassified exempt sale, an assignment treated as tax-free, a deposit routine that skips the till — none of these happens once. Whatever the flaw, it repeats in every return filed, so by the time CRA raises it, the question is not one adjustment but the same adjustment multiplied across years of reporting periods, plus interest and, where CRA alleges carelessness, penalties.
Exposure can also reach past the corporation. Directors can be held personally liable for GST/HST a company collected and failed to remit, which is why lenders, buyers, and boards treat unresolved HST/GST questions as more than an accounting detail. The discipline of this mandate is to size that exposure honestly — period by period, with the documentation on the table — before someone else does.
What Triggers a CRA HST/GST Audit?
The most common data-driven trigger is a mismatch between the revenue reported on a corporation's T2 income tax return and the revenue reported across its GST/HST returns for the same year. CRA compares the two filings electronically, and an unexplained gap is the most consistently cited GST/HST audit trigger. Legitimate reconciling items exist — exempt and zero-rated sales, timing differences, inter-company eliminations — but they need to be explainable on paper, ideally before CRA asks rather than after.
Beyond the revenue match, several patterns reliably draw attention:
- Returns that sit in a refund or credit position period after period
- Input tax credit ratios out of line with industry benchmarks
- Real estate activity — assignments, new housing rebate claims, self-supply events
- Cash-intensive operations, where CRA applies indirect verification by default
- Late, missing, or repeatedly amended GST/HST returns
- Supplier registration numbers that fail validation against CRA's GST/HST Registry
Why Does CRA Deny Input Tax Credits?
The single most common reason input tax credits are denied is missing or invalid supplier GST/HST registration numbers on the invoices behind the claim. The fix sounds trivial and is not: the number must belong to the supplier, be valid for the period, and verify against CRA's GST/HST Registry — and CRA checks.
The Excise Tax Act sets the documentary requirements in three tiers by invoice size:
An input tax credit documentation review works through the claims tier by tier: verifying supplier numbers against the registry, identifying which credits already meet the requirements, and rebuilding support where the rules permit — corrected invoices, supplier confirmations, contemporaneous evidence of the supply. Where a credit genuinely cannot be supported, it is better to know that number early and plan around it than to discover it in a proposal letter.
- Under $30 — the supplier's name, the invoice date, and the total amount paid or payable
- $30 to $149.99 — everything above, plus the supplier's GST/HST registration number and the tax amount shown separately or a statement that it is included
- $150 or more — everything above, plus the purchaser's name, the terms of payment, and a description sufficient to identify each supply
Where Does HST/GST Go Wrong in Real Estate?
Real estate produces the largest single-transaction HST/GST exposures this practice sees, and CRA operates a dedicated real estate compliance program with the GTA squarely inside it. The recurring problems are consistent: assignment sales of new construction treated as tax-free when they are generally taxable supplies; new housing rebate claims denied on occupancy or eligibility grounds; and builder self-supply obligations missed when a newly built unit is leased rather than sold.
The 2026 landscape adds a fresh trap. Ontario's enhanced HST New Housing Rebate covers 100% of the provincial portion on eligible new homes up to $1 million, for agreements entered into between April 2026 and March 2027 — but it largely excludes assignment sales. Investors modelling an assignment exit on the assumption the rebate travels with the deal are frequently modelling a number that does not exist.
For developers, builders, and investor groups, the useful work happens before positions harden: establishing the tax character of each project and each exit, documenting intention contemporaneously, and pricing HST into the deal rather than discovering it after closing. Where CRA has already raised a query — on an assignment, a rebate, or a self-supply — the same discipline applies in reverse: facts first, exposure quantified, then a deliberate response.
How Does CRA Test Cash Sales in an HST/GST Audit?
CRA does not take the books of a cash-intensive business at face value. In an HST/GST audit it applies indirect verification: bank deposit analysis that compares deposits to reported sales, markup and margin tests against industry benchmarks, and, where the gap is significant, net worth methods that shift the burden of proof onto the owner.
The restaurant sector shows the scale of that attention: CRA's compliance work in the sector has spanned more than 6,000 tax audits and identified $344 million in unreported income. Similar techniques reach convenience stores, salons, contractors, and any operation where cash is routine. When deposits and reported sales do not reconcile, CRA reads the difference as unreported revenue — with GST/HST assessed on top of the income tax consequence.
The response here is professional and factual: reconstruct the deposit trail, document the legitimate explanations — owner contributions, loans, transfers between accounts, exempt receipts — and quantify what genuinely cannot be explained. The work is organizing what is real, never concealing what is not. Owners who arrive with a reconciled deposit history stand in an entirely different position than owners who arrive with a shoebox.
Can HST/GST Errors Be Corrected Before CRA Raises Them?
Often, yes — and on materially different terms than after CRA calls. The Voluntary Disclosures Program was overhauled effective October 1, 2025. An unprompted general application — filed before CRA has signalled any contact — can bring full penalty relief and 75% relief on interest. A prompted partial application, made after CRA has communicated about the issue, brings 25% interest relief. The standard lookback is six years, ten for foreign-connected matters, and applications run through Form RC199.
The strategic point owners miss is sequencing. The unprompted tier is only available while it is available: an education letter, a GST/HST audit notice, even a phone call about the relevant period can close it. The correction conversation should therefore happen at the moment a problem is discovered — not after the next filing, not after year-end, and not once CRA's interest is confirmed.
A voluntary disclosure is also not the only path. Depending on the size, the cause, and the periods involved, the right instrument may instead be amended returns or a corrected go-forward position with documented controls. Choosing the path — and preparing the file so the chosen path holds — is judgment work, and it is exactly the kind of decision this mandate exists to support.
What Does Advisory Support Look Like During an HST/GST Audit?
Once a GST/HST audit is underway, discipline matters as much as argument. The practice acts as a single point of coordination: managing what is said and what is produced, responding to queries factually and on time, and presenting documentation as organized working-paper packages rather than raw fragments a CRA auditor must interpret alone.
Proposed adjustments are tested line by line and period by period — the arithmetic, the documentation tiers, the registry checks, the reconciling items — because proposals built from indirect methods often include amounts the records can properly displace. Where a notice of assessment issues, the 90-day objection window runs from its mailing date, and preserving that right on time frames everything that follows.
Where the matter carries penalty exposure, litigation risk, or privilege concerns, I coordinate with tax counsel — accountant communications are generally not privileged in Canada, and a well-structured file respects that from the first day. And because CRA can enforce collection of assessed GST/HST directly, including garnishment without a court order, collections posture is managed alongside the merits, not as an afterthought.
When this mandate applies
Situations this mandate typically covers
- A CRA letter announcing a GST/HST audit or pre-assessment review has arrived
- Input tax credits denied — or a proposal letter signalling they will be
- T2 and GST/HST filings that no longer reconcile
- An assignment sale, new housing rebate, or self-supply position under CRA query
- Cash deposits that will not tie to reported sales without work
- Multi-year documentation gaps discovered internally
- A GST/HST assessment with the 90-day objection window already running
- Lawyers, lenders, or buyers asking hard HST/GST questions inside a transaction
By the numbers
The figures that set the stakes
- of documentary requirements for input tax credits under the Excise Tax Act — under $30, $30 to $149.99, and $150 or more — each tier adding required invoice details
- 3 tiers
- interest relief — alongside full penalty relief — available on an unprompted general application under the Voluntary Disclosures Program rules effective October 1, 2025
- 75%
- in unreported income identified through CRA's restaurant-sector compliance work, spanning more than 6,000 tax audits
- $344M
of documentary requirements for input tax credits under the Excise Tax Act — under $30, $30 to $149.99, and $150 or more — each tier adding required invoice details
Source ↗interest relief — alongside full penalty relief — available on an unprompted general application under the Voluntary Disclosures Program rules effective October 1, 2025
Source ↗in unreported income identified through CRA's restaurant-sector compliance work, spanning more than 6,000 tax audits
Source ↗The engagement
How a private mandate runs
- 01
Confidential Consultation
A private conversation about the situation: the reporting periods involved, what CRA has said or sent, what the filings show, and which deadlines are already running. No documents are required at this stage.
- 02
Exposure Assessment
A structured, period-by-period review of returns, input tax credit support, deposits, and real estate positions. The output is a clear picture: where the exposure sits, how large it plausibly is, and how strong the documentation actually is.
- 03
Correction and Documentation Strategy
A deliberate plan for the file: a voluntary disclosure or amended filings where they fit, documentation rebuilt where the rules allow, and controls that stop the same flaw repeating in the next period.
- 04
CRA-Facing Management
Where a GST/HST audit or assessment is live: managed responses, organized document production, proposal-letter replies, objections filed inside the 90-day window, and tax counsel coordinated where the matter warrants it.
Illustration
How a matter like this is handled
- Situation
- A GTA distribution business with steady input tax credit claims received a CRA proposal letter following an HST/GST audit: a substantial block of credits spanning three years was to be denied, almost entirely because supplier invoices carried missing or invalid GST/HST registration numbers.
- Approach
- Every supplier was verified against CRA's GST/HST Registry and the claims were rebuilt tier by tier against the documentary requirements — corrected invoices and supplier confirmations obtained where the rules allowed, credits that genuinely could not be supported identified and conceded early, and related periods reviewed so the response addressed the whole exposure rather than the sample.
- Resolution
- The final assessment reflected the credits that truly lacked support rather than the full proposed denial, the exposure settled at a defined number the business could finance, and invoice-verification controls were put in place so the pattern would not rebuild in future periods.
This is an illustration of an engagement pattern, not a case report. Details are altered and combined to protect confidentiality, and nothing here predicts the outcome of any other matter — results depend entirely on the facts, the documentation, and the timing.
Frequent questions
Questions this raises
What should I do first when a CRA letter announces a GST/HST audit?
- Read it carefully, note every deadline and reporting period it names, and resist the instinct to phone the CRA auditor and explain. First conversations set the tone of the whole file, and unprepared explanations are difficult to walk back. Assemble the returns and workings for the periods named, establish what the documentation actually shows, and take advice before the first substantive contact. Representation before CRA is your right.
Why were my input tax credits denied?
- The single most common reason is missing or invalid supplier GST/HST registration numbers on the invoices behind the claim. Other frequent causes include invoices lacking the details required for their dollar tier, credits claimed on personal or exempt-use purchases, and amounts that cannot be traced to a business purpose. Some denials are recoverable: where the documentary requirements can properly be met, the position can often be rebuilt and defended.
What documentation does CRA require for an input tax credit?
- The Excise Tax Act sets three tiers by invoice size. Under $30: the supplier's name, the invoice date, and the amount paid or payable. From $30 to $149.99: add the supplier's GST/HST registration number and the tax amount, or a statement that it is included. At $150 or more: add the purchaser's name, the terms of payment, and a description sufficient to identify each supply. CRA applies these tiers strictly.
What is the T2 versus GST/HST return mismatch?
- CRA electronically compares the revenue reported on a corporation's T2 income tax return against the revenue reported across its GST/HST returns for the same year. Legitimate differences exist — exempt and zero-rated sales, timing differences, inter-company eliminations — but an unexplained gap is among the most common data-driven triggers for a GST/HST audit. The mismatch is best explained on paper, before CRA asks.
How far back can HST/GST exposure reach?
- GST/HST is assessed period by period, so the practical reach of a problem is the number of reporting periods the flaw touches and how many of them remain open. Periods for which no return was filed stay open, and misrepresentation can extend CRA's reach further. A recurring documentation flaw rarely stays in one quarter — quantifying the true multi-year exposure is the first step of this mandate.
Is HST payable on an assignment sale?
- Assignment sales of new-construction homes are generally taxable supplies — the assignment profit attracts HST, and CRA actively reviews pre-construction assignments in the GTA. Note also that Ontario's enhanced HST New Housing Rebate — 100% of the provincial portion on eligible new homes up to $1 million, for agreements from April 2026 to March 2027 — largely excludes assignment sales. Treating an assignment as tax-free is one of the most expensive assumptions in real estate.
Can I correct HST/GST errors through the Voluntary Disclosures Program?
- Often, yes — if CRA has not already raised the issue. Under the rules effective October 1, 2025, an unprompted general application can bring full penalty relief and 75% interest relief; a prompted partial application brings 25% interest relief. The standard lookback is six years, ten for foreign-connected matters. Eligibility and sequencing are judgment calls: the unprompted tier can close the moment CRA signals contact, so timing matters more than most owners expect.
What happens if the 90-day objection window is missed?
- A GST/HST assessment can be objected to within 90 days of its mailing date. If that window is missed, an application for an extension of time may be available within the following 12 months — but it must justify the delay and is not automatic. Beyond that, rights narrow sharply. If an assessment exists anywhere in your file, establishing the exact dates is the first task, before any strategy discussion.
Will a GST/HST audit spread into income tax?
- It can. The same bank deposit analysis that tests reported sales for GST/HST purposes also tests income for corporate or personal tax purposes, and CRA routinely coordinates the two. Responses should therefore be prepared with the whole picture in mind: an explanation offered casually in an HST/GST audit can surface later in an income tax reassessment. One coordinated position, consistently documented, serves both files.
Do you deal with the CRA auditor directly?
- Yes, where the mandate calls for it. As an authorized representative, I can manage CRA-facing communication — queries, document production, working-paper packages, and proposal-letter responses — so information flows deliberately rather than reactively. Where privilege or litigation posture matters, I coordinate with tax counsel; accountant communications are generally not privileged in Canada, and the file is structured with that in mind.
Do you act only in Mississauga?
- The practice is based in Mississauga and works across the GTA and Ontario, but GST/HST is federal law and CRA practice is national — engagements are not geographically limited. Most mandates run through private consultation, document exchange, and WhatsApp or scheduled calls, so distance rarely affects the work. What matters is the file, the periods at issue, and the deadlines already running.
This page reflects Canadian tax law and CRA administrative practice as of July 10, 2026. It is general information, not tax, accounting, or legal advice.
Further reading
Related insights
If HST/GST Exposure Is Building, Address It Before CRA Does.
The options in an HST/GST matter narrow in a fixed order: the unprompted voluntary disclosure tier closes when CRA makes contact, positions harden during the CRA audit, and the 90-day objection clock starts the day an assessment is mailed. Wherever your situation sits on that line, the useful conversation is the one that happens now — private, factual, and without obligation.
Private consultations available by request. WhatsApp: +1-647-510-8878. Personally answered — typically within business hours.