GST/QST on Vehicle Use for Business in Quebec: Rules for ITCs/ITRs, Mileage Logs, and Mixed-Use Deductions

Introduction

Vehicles are one of the most audited expense categories for GST/QST purposes in Quebec.
Whether you’re self-employed, incorporated, or operating a fleet, Revenu Québec closely monitors how businesses claim input tax credits (ITCs) and input tax refunds (ITRs) for fuel, repairs, leasing, financing, and vehicle purchases.
The rules become even more complicated when the vehicle is used for both business and personal purposes — which is the case for most taxpayers.
This guide explains how GST/QST applies to vehicle expenses in Quebec, how to calculate business-use percentages, and what documentation is required to survive an audit.

Legal and Regulatory Framework

Under the Excise Tax Act (GST) and Quebec Taxation Act (QSTA):

• ITCs/ITRs are allowed only on the portion of vehicle expenses used in commercial activity.

• Personal use must be excluded from claims.

• Registrants must maintain contemporaneous mileage logs.

• Special rules apply to passenger vehicles vs. motor vehicles.

• Capital cost allowance categories (Class 10/10.1) do not determine ITC eligibility — GST/QST rules are separate.

• Expenses must be supported by valid invoices with GST/QST breakdown.

Authorities enforce:

• ETA s.169(4)/QSTA s.39 (documentation requirements)

• ETA s.141.01/QSTA equivalents (commercial-activity test)

• ETA s.286/QSTA s.24 (record-keeping obligations)

• Penalty provisions for negligence or false statements

Key Court Decisions

Courts have consistently held that:

• Estimates like “80% business use” are not accepted without mileage logs.

• Mileage logs must include date, destination, purpose, starting and ending odometer reading.

• Reconstructed logs may be accepted only when supported by independent evidence (contracts, delivery slips, location history).

• Home-to-work travel is considered personal use, even for incorporated business owners.

• Vehicle ITCs/ITRs may be denied entirely if record-keeping is insufficient.

These decisions show that documentation is the deciding factor.

Why CRA and Revenu Québec Target These Issues

Vehicle expenses are high-risk because:

• Many claim unrealistically high business-use percentages.

• Mileage logs are often incomplete or nonexistent.

• Vehicles are frequently purchased in personal names but expensed by the business.

• Gas receipts and invoices often lack GST/QST numbers.

• Mixed-use expenses (insurance, repairs, lease payments) require proper proration.

• Large ITC/ITR claims or first-year claims trigger audit indicators.

Industries most targeted include trades, sales, consultants, delivery drivers, contractors, and real estate professionals.

Mackisen Strategy

We help businesses calculate accurate, audit-proof vehicle-use percentages.

1. Complete Mileage Log System

We set up:

• CRA-approved mileage log templates

• Monthly reconciliation

• Odometer readings at start/end of year

• Digital tracking options when applicable

2. Business-Use Allocation

We calculate:

• Percentage based on total kilometres driven

• Exclusion of personal/home-to-work kilometres

• Allocation of mixed-use expenses (fuel, insurance, repairs)

• Special rules for fleet vehicles

3. ITC/ITR Eligibility Review

We check:

• Fuel and maintenance invoices

• Lease payments vs. financing charges

• Vehicle purchase GST/QST treatment

• Restrictions for passenger vehicles

• Capital improvement expenses

4. Documentation & Invoice Compliance

We verify:

• GST/QST numbers on receipts

• Adequate descriptions

• Proof of payment

• Proper naming (personal vs. business)

5. Audit Defence

If Revenu Québec questions your vehicle claims, we prepare:

• Mileage analysis

• Backup documentation

• Legal arguments referencing ETA/QSTA

• Full representation until the matter is resolved

Real Client Experience

A real estate broker claimed 90% business use on her SUV without a mileage log.
Revenu Québec denied over $5,800 in GST/QST credits.
Mackisen reconstructed a defensible mileage log based on her listings, client visits, and travel history, reducing the reassessment by nearly half.
This case demonstrates how strong reconstruction and documentation can prevent major penalties.

Common Questions

1. Can I claim ITCs/ITRs on a vehicle used personally and for business?
Yes — but only for the business portion, supported by mileage logs.

2. Is commuting to my office considered business use?
No. Home-to-office travel is personal use, even for business owners.

3. Can a corporation claim ITCs on a vehicle owned personally by the shareholder?
Potentially, but documentation and reimbursement policies must be exact.

4. Are gas receipts without GST/QST numbers valid?
No. Credits may be denied without proper invoices.

Why Mackisen

With more than 35 years of combined CPA experience, Mackisen CPA Montreal helps businesses stay compliant while recovering the taxes they're entitled to. Whether you're reporting vehicle expenses, preparing GST/QST returns, or defending an audit, our expert team ensures precision, transparency, and protection from audit risk.