How to Prepare for a CRA Corporate Tax Audit

A Notice of Audit isn’t an accusation - it’s a verification process. But it’s a process with real teeth: penalties, interest, and reassessments that can roll back years of filings. The outcome is almost entirely a function of preparation, not negotiation. The CRA’s mandate is to ensure the tax base is protected, and they use sophisticated data-matching to find discrepancies.

What actually triggers an audit

Audits are rarely random. They are driven by risk scoring and industry benchmarking. The CRA compares your business’s performance against others in your same postal code and NAICS code.

The "Lifestyle" or Net Worth Audit If your corporation reports $30,000 in income, but you live in a $3M home and drive two luxury SUVs, the CRA may perform a "Net Worth" audit. They analyze your personal assets and bank accounts and "work backward" to calculate how much income you *must* have earned to support that lifestyle. Any gap is taxed as unreported income.

The three CRA review levels

1. 01Desk Review / Pre-assessment: A letter requesting specific documentation for a specific line item (e.g., "Please provide receipts for Line 8523 - Meals").
2. 02Field Audit: An auditor visits your premises or requests a full digital upload of your GL. They typically cover 1–3 fiscal years.
3. 03Special Investigations: Handled by the enforcement division. This occurs when fraud or systemic evasion is suspected.

Build the audit-ready file before you ever get a letter

A clean file means:

• Cloud Accounting (QBO/Xero): Reconciled monthly to bank statements.
• Digital Receipt Capture: Tools like Dext or Hubdoc ensure that a digital copy of the receipt is permanently "attached" to the transaction.
• The Minute Book: Audits often start with a request for your corporate minute book. If your resolutions for dividends and bonuses aren’t signed and dated, the CRA may recharacterize those payments as taxable benefits.

Worked Example: The Cost of a "Bad" Audit (2026)

Imagine you are audited for the 2024 tax year. The auditor finds $20,000 of "business travel" that was actually a family vacation and denies the deduction.

• Corporate Tax Reassessment: $20,000 x 12.2% = $2,440.
• Personal Benefit Reassessment: The $20,000 is added to your personal income (Subsection 15(1)). Tax at 53.53% = $10,706.
• Gross Negligence Penalty (50%): If deemed intentional, 50% of the tax = $6,573.
• Arrears Interest (approx 9%): For 2 years = ~$2,400.
• Total Cost of a $20,000 "error": ~$22,119.

You end up paying more in penalties and interest than the original "savings."

What to do in the first 48 hours after the letter

1. 01Don’t respond verbally. Acknowledge receipt in writing only.
2. 02Authorize your accountant (Form AUT-01) so all communication routes through them.
3. 03Read the request carefully. Note the scope, the years, and the deadline.
4. 04Pull only the documents requested. Never give the auditor "everything" in hopes they go away. Only provide exactly what was asked for.

When the Proposal Letter arrives

The CRA issues a Proposal Letter before finalizing. You have 30 days to respond. This is the most important window.

• If you agree with the findings, you sign and pay.
• If you disagree, you must provide a "Rebuttal" with reconciled evidence.

A well-argued response to a proposal letter, with case law citations and reconciled supporting evidence, frequently reduces or eliminates the reassessment before it becomes a formal Notice of Reassessment.