Insights
Nov 12, 2025
Mackisen
How to Navigate a Revenu Québec Audit Step-by-Step
Introduction
A Revenu Québec audit can be one of the most stressful experiences for any business owner. Whether you’re a small retailer, contractor, or professional consultant, that first letter or phone call from Revenu Québec can trigger fear and uncertainty. But an audit does not automatically mean wrongdoing—it is a verification process to confirm that your GST/QST, payroll, and income tax filings accurately reflect your books.
At Mackisen CPA Montreal, we’ve helped Quebec businesses of every size handle audits with confidence. Our team of CPA auditors, tax lawyers, and compliance professionals has represented clients in hundreds of Revenu Québec audits, saving them millions in penalties and protecting their reputations. This detailed guide explains how to navigate a Revenu Québec audit step-by-step, what the law allows auditors to do, and how to defend your business professionally and successfully.
Legal and Regulatory Framework
Revenu Québec’s audit powers are defined by the Tax Administration Act (Quebec), which grants the agency authority to verify and reassess tax filings.
Section 39 — Authorizes Revenu Québec auditors to examine your books, visit your business, and request documentation.
Section 93 — Allows the issuance of a Notice of Reassessment for unpaid or incorrectly reported taxes.
Section 94.1 — Provides a mechanism for taxpayers to request relief from penalties and interest if errors occurred in good faith.
Section 59(3) — Establishes daily compounding interest on overdue balances.
These sections apply to QST, GST (administered jointly by CRA and ARQ in Quebec), payroll deductions, and corporate tax. Ignoring an audit or failing to cooperate can result in automatic assessments based on estimates—often much higher than the real amount.
Why Revenu Québec Audits Businesses
Revenu Québec uses artificial intelligence and data cross-matching to detect inconsistencies in tax reporting. Some common triggers include:
Declared revenues lower than industry averages.
Large or recurring Input Tax Refunds (ITRs).
Missing or late filings.
Inconsistencies between bank deposits and declared sales.
Discrepancies between supplier and client QST reports.
A proactive understanding of how audits work and how to respond helps protect you from unnecessary penalties.
Step-by-Step: How to Navigate a Revenu Québec Audit
Step 1: The Audit Notice
You’ll receive an Audit or Verification Letter outlining the years, taxes, and documents under review. This is your opportunity to prepare and show good faith. Contact your accountant immediately. Mackisen CPA helps clients draft a professional acknowledgment letter confirming cooperation and timelines.Step 2: Document Preparation
Revenu Québec typically requests:General ledger, journals, and trial balance.
Sales and purchase invoices.
Bank statements and reconciliations.
Payroll summaries and contractor T4A/RL-1 slips.
Supporting receipts for QST Input Tax Refunds (ITRs).
All records must cover the audit period, usually 2–4 years. Maintain both digital and paper copies, and ensure all data is internally consistent.
Step 3: The Auditor’s Review or Visit
Audits may occur remotely or on-site. During this phase, the auditor examines:Whether QST was correctly charged and remitted.
If input tax refunds were properly claimed.
Whether sales figures reconcile with deposits.
How invoices were documented and categorized.
Under Tax Administration Act s.39, you must allow the auditor access to relevant documents—but you also have rights. Mackisen CPA ensures that information provided remains limited strictly to the scope of the audit.
Step 4: Follow-Up Questions
Auditors often request clarification or additional records. Always respond promptly and factually. Avoid assumptions or speculative explanations. Our audit defense team drafts clear, legally compliant answers supported by documentary proof.Step 5: Proposed Adjustments
If the auditor finds discrepancies, you’ll receive a Proposed Notice of Assessment summarizing their findings and recommended adjustments. You usually have 30 days to respond. This is your chance to correct misunderstandings or provide additional evidence before the assessment becomes final.Step 6: The Final Notice of Assessment
After your response, Revenu Québec issues a Final Notice of Assessment. If you disagree, you have 90 days under Tax Administration Act s.93.1 to file a formal Notice of Objection. Mackisen CPA’s tax lawyers handle this process from start to finish, preparing submissions and negotiating directly with Revenu Québec’s litigation department.Step 7: Post-Audit Compliance
Once the audit closes, implement improved systems: monthly reconciliations, automated QST tracking, and professional oversight. Our post-audit reviews help clients prevent future red flags.
Jurisprudence and Lessons from Audit Cases
Quebec courts consistently reinforce the need for clear records and cooperation:
Lac d’Amiante du Québec Ltée (SCC 2001) – Revenu Québec has the right to request and inspect business records to ensure compliance.
Canderel Ltd. v. Canada (SCC 1998) – Tax filings must reflect actual commercial reality, not estimates or assumptions.
Hickman Motors Ltd. v. Canada (SCC 1997) – CRA and Revenu Québec assessments are presumed valid until proven otherwise by the taxpayer.
Royal Bank of Canada v. The Queen (FCA 2012) – Penalties must be justified, but taxpayers carry the burden of providing proof of accuracy.
These decisions highlight the importance of documentation and consistency—your best legal defense during an audit.
Documentation: Your Audit Shield
Revenu Québec auditors don’t rely on trust—they rely on proof. Protect yourself with:
A six-year archive of invoices, receipts, and bank records.
Monthly reconciliations showing taxes collected vs. remitted.
Proof of QST registration and supplier numbers.
Payroll and contractor payment summaries.
Copies of all correspondence with auditors.
At Mackisen CPA Montreal, we prepare an audit binder for every client—a professionally indexed file containing all key documents and legal references. This approach demonstrates transparency, organization, and professionalism, immediately reducing audit tension.
How Revenu Québec Conducts Data Analysis
Today’s audits are algorithm-driven. Revenu Québec compares your records to:
Supplier filings (cross-verification of QST numbers).
Industry data on revenue-to-expense ratios.
Banking and merchant processor transactions.
Payroll slips (RL-1 and T4 data).
If your ratios deviate significantly from norms, the system automatically flags your business. Mackisen CPA runs pre-audit diagnostic tests using the same algorithms to identify potential risks before Revenu Québec does.
Winning With Revenu Québec
Success in an audit is not about arguing—it’s about preparation and professionalism. Our 35+ years of experience have shown that businesses win audits by presenting accurate evidence and demonstrating compliance under law.
Our step-by-step approach includes:
Pre-Audit File Review – We reconstruct and verify every record before submission.
Representation – Our CPA auditors and tax lawyers manage all auditor communications.
Evidence Submission – Every claim is documented and cross-referenced with legal statutes.
Negotiation – We use Tax Administration Act s.94.1 to reduce or remove penalties for good faith errors.
Post-Audit Strategy – We install new systems to prevent future reassessments.
Mackisen Service Hub: Your Audit Defense Partner
The Mackisen Service Hub is Montreal’s comprehensive audit defense and compliance center. Our services include:
Audit preparation and risk analysis.
Direct representation before Revenu Québec and CRA.
Voluntary disclosure and penalty relief applications.
Compliance training for accounting staff and business owners.
Every team member—CPA auditor, tax lawyer, or bookkeeper—is trained in Quebec tax law and has experience dealing directly with Revenu Québec’s audit and litigation departments.
Real Client Example
A Montreal contractor was reassessed $220,000 for disallowed QST Input Tax Refunds. Mackisen CPA reconstructed missing supplier records, presented compliance proof, and negotiated directly with the ARQ legal team. Using Tax Administration Act s.94.1, penalties were waived and the reassessment was reduced by 93%.
Why Mackisen
With more than 35 years of combined CPA and legal expertise, Mackisen CPA Montreal is Quebec’s trusted firm for audit representation and tax compliance. We know the law, we understand the system, and we defend our clients with strategy and precision.
When Revenu Québec calls, Mackisen ensures you answer with confidence—organized, professional, and protected.
