How One Retailer Avoided $10,000 in QST Penalties with Professional Help

A Montreal retailer was shocked to receive a notice from Revenu Québec proposing nearly $10,000 in QST penalties and interest. The business had inconsistent bookkeeping, incorrect POS tax settings, and multiple filing errors that accumulated over several reporting periods. What seemed like a small mistake snowballed into a major compliance issue until professional intervention changed everything.

This case study shows how the retailer avoided the penalties, corrected its filings, and restored full compliance in record time.

The Situation

The retailer operated a busy storefront with:
• high daily transaction volume
• multiple payment channels (debit, credit, e-commerce)
• a POS system that hadn’t been properly configured
• inconsistent cash-register Z-reports
• bookkeeping months behind

When Revenu Québec reviewed the QST filings, they found:
• mismatched sales totals
• incorrect GST/QST tax coding
• missing POS summaries
• bank deposits that didn’t align with reported revenue
• duplicate entries

This triggered a full QST audit.

The Auditor’s Findings

The auditor proposed adjustments for:
• underreported sales
• incorrect QST calculations
• missing documentation for ITCs/ITRs
• late filings
• discrepancies between POS reports and bank deposits

Total proposed penalties and interest exceeded $10,000.

The auditor also warned that:
• future returns would be monitored
• missing documentation could lead to denial of credits
• the business might face stricter compliance controls

How Mackisen Turned the Audit Around

Step 1 — POS System Diagnosis and Correction

Mackisen reviewed the retailer’s POS system and identified:
• outdated tax settings
• incorrect GST/QST coding
• missing tax rules for certain product categories
• rounding issues
• unrecorded gift-card redemptions

The POS was corrected and synced with accounting software.

Step 2 — Full Bookkeeping Cleanup

The team reconstructed:
• monthly sales summaries
• cash register Z-reports
• merchant statements
• reconciled deposits with daily sales
• corrected duplicated or missing entries

This created a clean and accurate audit trail.

Step 3 — Documentation Rebuild

Mackisen prepared:
• complete ITR/ITC schedules
• backup documents for all expenses
• corrected QST calculations
• organized receipts
• clear explanations for discrepancies

Everything was indexed into a professional audit binder.

Step 4 — Negotiation With the Auditor

A CPA communicated directly with the auditor and:
• challenged incorrect assumptions
• proved certain adjustments were unnecessary
• demonstrated that discrepancies were clerical, not intentional
• provided full reconciliation of deposits to sales
• secured removal of penalties
• reduced interest significantly

The Result

The audit closed with:
• $10,000 in penalties avoided
• interest reduced dramatically
• full acceptance of corrected filings
• no further adjustments
• POS system fully compliant
• future filings aligned with RQ expectations

The business kept all its input tax refunds and avoided serious financial consequences.

Key Lessons

• POS systems must be configured correctly for GST/QST
• mismatched sales and deposits trigger audits
• proper documentation can eliminate penalties
• CPA involvement dramatically changes audit outcomes
• bookkeeping delays cost businesses money

Common Questions

Why were the penalties so high?
Errors accumulated over multiple periods, creating compounding penalties and interest.

Can a retailer be penalized for POS system mistakes?
Yes even software errors are the business’s responsibility.

Can penalties be removed?
Often, yes if discrepancies are clearly explained and documented.

What’s the fastest way to fix QST filing issues?
Professional bookkeeping cleanup and a CPA-led defense.

Mackisen Strategy

Mackisen CPA helps retailers:
• configure POS systems
• reconcile daily sales and deposits
• correct QST/GST coding
• prepare audit-ready documentation
• negotiate with Revenu Québec
• avoid penalties in future filings

We turn stressful audit situations into success stories.

 Why Mackisen

With more than 35 years of combined CPA experience, Mackisen CPA Montreal helps businesses recover lost GST/QST refunds, correct bookkeeping issues, and prevent future refund delays. We turn refund problems into refund success stories.