CRA GST/HST Large Corporation Audit — Montreal CPA Firm Near You: High-Risk, High-Complexity Sales Tax Defense

A CRA GST/HST Large Corporation Audit is one of the most intensive and complex sales-tax audits conducted by the Canada Revenue Agency. These audits target corporations with multi-provincial operations, large transaction volumes, cross-border activities, complex supply chains, or recurring multi-million-dollar refund claims.
Mackisen CPA Montreal specializes in defending large corporate audits by building CPA-certified audit binders, analyzing place-of-supply rules, reconstructing Input Tax Credit (ITC) trails, and ensuring your GST/HST systems meet CRA’s strict standards.

Large-corporation audits are not about simple filing mistakes — they focus on tax-logic, intercompany flows, compliance controls, and audit-proof documentation.

Legal Foundation

Excise Tax Act s.165–169 — defines GST/HST charging, collecting, and ITC eligibility.
Excise Tax Act s.286 — requires corporations to maintain complete audit-ready records and invoicing.
Excise Tax Act s.288 — grants CRA broad powers to inspect electronic records, ERP systems, and internal audit logs.
Jurisprudence: Northwest Company Inc. v. Canada — CRA can deny ITCs even when GST/HST was paid if documentation is incomplete.

Learning insight: Large corporations are judged on systems, not just transactions. CRA tests your controls as much as your numbers.

Why CRA Audits Large Corporations for GST/HST

CRA flags large corporate files due to:
• multi-province operations requiring complex place-of-supply analysis
• large recurring refund claims, especially in construction, manufacturing, logistics, or wholesale
• heavy use of subcontractors (verification of registration, invoices, and ITC eligibility)
• discrepancies between ERP data, financial statements, and GST/HST returns
• cross-border transactions involving imports, exports, or digital services
• complex intercompany transactions and shared-services allocations
• supplier risk indicators (invalid GST numbers, non-compliant vendors)

Learning insight: CRA assumes complexity = risk. Your CPA must demonstrate complexity = compliance.

CRA GST/HST Large-Corp Audit Process

1. CRA forms a Large Business Audit Team (sales-tax specialist, systems auditor, manager).

2. CRA requests multi-year records, ERP extracts, contracts, invoices, intercompany ledgers, and payment proofs.

3. CRA validates ITCs by sampling suppliers, checking registration numbers, and tracing payments.

4. CRA performs place-of-supply testing for every province involved (5%, 13%, 15%).

5. CRA reviews intercompany charges (management fees, cost shares, royalty flows).

6. CRA tests GST on imports, self-assessed tax, drop shipments, and fulfillment-center transactions.

7. CRA issues a Proposed Audit Adjustment Letter.

8. Mackisen CPA responds with technical rebuttals, reconstructions, and tax-law arguments.

Learning insight: Large business audits are won when your documentation mirrors CRA’s internal audit format.

Mackisen CPA’s Large Corporation GST/HST Defense Strategy

• validate every ITC: invoices, tax amounts, supplier GST/QST registration, payment traceability
• rebuild missing ITC trails using supplier confirmations
• prepare full place-of-supply matrix for 5%, 13%, and 15% jurisdictions
• reconcile ERP GL accounts with GST/HST filings
• create ITC binders organized in CRA’s preferred audit sequence
• defend intercompany charges using transfer-pricing principles
• verify import GST self-assessment under ETA s.218.01
• defend zero-rating for exports with customs proofs, bills of lading, shipping logs
• submit CPA-certified audit briefs with legal-tax analysis
• negotiate penalty and interest reductions where CRA overreaches

Learning insight: CRA listens when the file is stronger than their assumptions — and built in their own audit language.

Common CRA Findings in Large-Corp GST/HST Audits

• denied ITCs due to incomplete invoices
• invalid GST numbers from subcontractors
• incorrect place-of-supply calculations
• ITCs claimed without proof of payment
• missing import documentation or incorrect self-assessment
• non-arm’s-length intercompany charges lacking economic substance
• double-claimed ITCs across fiscal periods
• misclassified exempt vs. zero-rated vs. taxable supplies

Learning insight: 80% of GST/HST reassessments for large corporations result from documentation gaps, not tax mistakes.

Real-World Results

• A national distributor recovered $1.8M in frozen refunds after Mackisen CPA rebuilt ITC documentation and place-of-supply logic.
• A construction group avoided a $740,000 GST reassessment after we validated subcontractor GST numbers and corrected ITC allocations.
• A logistics corporation overturned $520,000 in adjustments by proving correct zero-rating for exports with complete shipping proofs.
• A retail chain prevented a $900,000 intercompany adjustment after we structured a defensible economic-substance file.

Learning insight: CRA withdrawals happen when your CPA presents documentation that CRA cannot dispute.

SEO Optimization and Educational Value

Primary keywords: GST/HST large corporation audit, CRA large business audit, Mackisen CPA Montreal, corporate GST defense, ITC audit Canada
Secondary keywords: place of supply audit, intercompany GST/HST audit, ERP GST reconciliation, GST refund audit, CRA audit defense Montreal

Learning insight: Clear, authoritative content strengthens both audit defense and SEO authority.

Why Mackisen CPA Montreal

With over 35 years of corporate audit experience, Mackisen CPA Montreal is one of Québec’s leading firms for GST/HST large-corporation audit defense. Our bilingual team of CPAs, systems auditors, and indirect-tax specialists build audit files that withstand CRA’s highest level of scrutiny.

Learning insight: Large audits test systems, controls, and evidence. We ensure all three are airtight.

Call to Action

If CRA has initiated a GST/HST Large Business Audit or frozen your refunds, immediate professional defense is critical.
Contact Mackisen CPA Montreal for complete audit representation and compliance reconstruction.
Phone: 514-276-0808 | Email: info@mackisen.com | Website: mackisen.com

Learning conclusion: A CRA GST/HST Large Corporation Audit tests the strength of your systems, documentation, and tax logic. Mackisen CPA Montreal ensures all three meet CRA’s highest standards — protecting your corporation from multi-million-dollar adjustments.