What triggers a CRA audit?

Common triggers include large deductions relative to income, math errors, unreported income (CRA cross-references T4s/T5s), high home office claims, cash businesses, significant year-over-year changes, and random selection. Self-employed individuals face higher scrutiny.

How common are CRA audits?

Full audits are relatively rare — about 1-2% of returns. However, CRA "reviews" (requests for documentation) are more common. Self-employed returns, cash businesses, and returns with unusual deductions are audited at higher rates.

How far back can CRA audit?

CRA can generally audit 3 years back from the date of your Notice of Assessment. For suspected fraud or if you didn''t file, there''s no time limit. CRA can also audit 6 years back in certain cases involving foreign income reporting.

CRA Audit Triggers: What Increases Your Chances of Being Audited (2026)

The word “audit” can be intimidating, but the reality is that full CRA audits affect only about 1-2% of returns — and most reviews are simple document requests that resolve quickly. That said, CRA’s automated matching has become remarkably sophisticated: every T4, T5, and property transaction is cross-referenced against your return, and cash-heavy businesses, self-employed filers, and returns with large deductions relative to income draw the most scrutiny. The best defence is simple — claim what you’re entitled to, keep receipts, and report all income.

After understanding the triggers, move to response pages how to respond to a CRA audit and why did CRA reassess my taxes. If risk remains, use how to dispute a CRA assessment or reassessment and the CRA Voluntary Disclosures Program guide.

Types of CRA Reviews

Type	Description	Frequency
Processing review	Quick check during initial assessment	Common
Matching review	Comparing your return to T4/T5 slips	Very common
Pre-assessment review	Before issuing assessment	Occasional
Desk audit	CRA requests documents by mail	Moderate
Field audit	In-person at your home/business	Rare
Net worth audit	Lifestyle vs reported income	Rare, cash businesses

Top CRA Audit Triggers

High-Risk Deductions

Deduction	Why It’s a Trigger
Home office expenses	Frequently overclaimed
Vehicle expenses	Personal vs business blurred
Meal and entertainment	Often exaggerated
Travel expenses	Need clear business purpose
Cash expenses without receipts	Red flag
Charitable donations (large)	Especially if unusual

Self-Employment and Business

Factor	Audit Risk
Cash-heavy business	High risk
Reporting losses year after year	Red flag
High expense-to-income ratio	Triggers review
Significant revenue fluctuations	Draws attention
Large inventory claims	Needs documentation
Bartering income	Often unreported

Employment Deductions

Claim	Risk Level
Home office (employee)	Higher scrutiny post-COVID
Union dues	Low (matched by union)
Tools deduction	Must match profession
Moving expenses	Distance rules apply
Employment expenses (T2200)	Need signed form

What CRA Cross-References

Automatic Matching

CRA Knows About	Source
Employment income	T4 from employer
Investment income	T5 from banks
RRSP contributions	Receipts from institutions
TFSA overcontributions	Financial institutions
Home sales	Land registry
Rental income	Property records
Child care providers	Recipient claims

Third-Party Information

Information	How CRA Gets It
Large cash transactions	Bank reports ($10,000+)
Real estate transactions	Land title registry
Vehicle purchases	Registration records
International transfers	FINTRAC
Cryptocurrency	Exchange reporting
Contractor payments	Matching to payer claims

Red Flags by Situation

For Employees

Red Flag	Why
Claiming expenses without T2200	Form required
Large vehicle claims	Need employer certification
Excessive home office	Requires dedicated space
Inconsistent with T4 income	CRA notices

For Self-Employed

Red Flag	Why
Continuous business losses	Should be profitable eventually
Personal expenses as business	Common abuse
100% vehicle business use	Unlikely realistic
Large cash revenue, low reported	Lifestyle mismatch
Missing GST/HST registration	If revenue exceeds $30,000

For Investors

Red Flag	Why
Unreported foreign income	Serious offense
TFSA overcontribution	Automatic penalty
Day trading in TFSA	May be reclassified as business
Large capital gains, no reporting	Property sale matching
T1135 foreign property not filed	$100,000+ foreign assets

How CRA Selects Returns

Selection Methods

Method	Description
Random selection	Small % completely random
Computer scoring	Returns scored for risk
Industry campaigns	Targeting specific sectors
Referrals	Tips, other audits
Prior audit history	If issues found before
Statistical outliers	Claims outside normal range

CRA doesn’t just look at individual returns in isolation — it compares yours against statistical norms for your industry, income level, and region. A restaurant owner reporting $80,000 in revenue with $75,000 in expenses will trigger scrutiny because the margins are far below industry averages. Similarly, claiming 100% business use of a vehicle is almost never accepted; even CRA auditors acknowledge a reasonable personal-use component. Using tax software with auto-fill reduces matching errors, and keeping a simple mileage log or home office measurement can resolve most desk audits within a single letter.

Industries Under Scrutiny

Industry	Why
Construction	Cash payments common
Restaurants	Cash tips, inventory
Real estate	Complex transactions
Cannabis	New industry, compliance focus
Trucking	High deduction claims
Trades	Cash work

How to Reduce Audit Risk

Good Record-Keeping

Practice	Benefit
Keep all receipts	Prove deductions
Log vehicle use	Mileage log
Document home office	Separate space, measurements
Bank records	Corroborate income/expenses
Keep records 6+ years	CRA can go back

Accurate Reporting

Best Practice	Why
Report all income	CRA cross-references
Don’t round aggressively	Exact numbers seem accurate
File on time	Late filing increases scrutiny
Claim only legitimate deductions	Don’t get greedy
Get professional help if complex	Worth the cost

Specific Tips

Situation	Action
Large charitable donations	Get official receipts
Home office	Calculate properly, keep records
Vehicle expenses	Detailed mileage log
Foreign assets	File T1135 if over $100,000
Rental income	Report all, deduct legitimately

What Happens During an Audit

Typical Process

Stage	What Happens
1. Selection	Return flagged for review
2. Notification	Letter from CRA
3. Information request	Specific documents requested
4. Review	CRA examines documents
5. Proposal	CRA proposes changes (if any)
6. Response	You agree or dispute
7. Assessment	Final determination
8. Appeal	If you disagree

Your Rights

Right	Details
Representation	Accountant or tax lawyer
Documentation	CRA must show why
Appeal	Formal objection process
Fairness	Taxpayer Bill of Rights
Privacy	Your information protected

What to Do If Audited

Step	Action
1	Don’t panic
2	Read the letter carefully
3	Gather requested documents
4	Respond by deadline
5	Consider professional help
6	Be honest and cooperative
7	Appeal if you disagree

The Bottom Line

Most CRA reviews are routine document checks, not full-blown audits. Keep organized records for at least six years, report all income (CRA already knows about it from T4s, T5s, and property registries), and claim only deductions you can substantiate with receipts. If you do receive an audit letter, respond on time, consider hiring an accountant, and remember that the Taxpayer Bill of Rights protects your ability to appeal any reassessment.