Bookkeeping Mistakes That Trigger CRA Audits

No Calgary business owner wants to deal with a CRA audit. While audits can be random, certain bookkeeping mistakes significantly increase your chances of being selected for review. Here are the most common red flags — and how to avoid them.

1. Inconsistent Revenue Reporting

If the income on your tax return doesn't match your GST filings, bank deposits, or T4A slips, CRA's matching algorithms will flag the discrepancy. Accurate, consistent bookkeeping ensures all your filings tell the same story.

2. Excessive Business Expense Claims

Claiming business expenses that are disproportionately high relative to your revenue is a red flag. This is especially true for meals and entertainment, vehicle expenses, and home-office deductions. The key is to claim only legitimate business expenses and keep supporting documentation.

3. Round Numbers

If your expense claims are suspiciously round ($500, $1,000, $2,000), it suggests estimation rather than actual record-keeping. Real expenses have real, specific dollar amounts. Always use actual figures from receipts and invoices.

4. Cash-Heavy Businesses

Restaurants, salons, and trades businesses that handle a lot of cash are inherently higher-risk from CRA's perspective. If your reported revenue seems low relative to your industry benchmarks or business size, expect questions. The solution is meticulous tracking of all cash transactions.

5. Repeated Late Filings

Chronically late GST or tax filings signal disorganisation — and CRA may wonder what else is being mismanaged. Filing on time, every time, keeps you off the radar.

6. Claiming Personal Expenses as Business

This is one of the most common audit triggers. Personal cell phone bills, personal vehicle use, and personal meals cannot be claimed as business expenses unless there's a genuine business purpose — and the personal portion must be excluded.

Your Best Defence: Clean Books

Accurate, well-organised bookkeeping is the single best defence against a CRA audit. When every transaction is properly categorised, every receipt is retained, and every filing is consistent and timely, you have nothing to worry about. Castle Bookkeeping helps Calgary businesses maintain CRA-ready books year-round.