By OptiVal Editorial Desk
Ask a room of small business owners what triggers a CRA audit and you will hear a lot of folklore. The real risk factors are far more boring: patterns in your numbers, gaps in your paperwork, and timing that does not add up. This guide covers the nine things that genuinely raise your chances of a CRA review, and what to do about each one.
How the CRA actually picks audit files
The CRA does not read every return by hand. It runs risk-assessment models that compare your return against your own history and industry benchmarks, and it matches your reported income against third-party slips like T4s, T5s, T4As, and GST/HST filings. Files with the highest risk scores get pulled for review.
Other paths exist too: random selection (yes, really), targeted compliance projects in specific industries, confidential tips through the CRA’s Leads Program, and simply failing to file. An audit is not proof of wrongdoing. It means the CRA has selected one or more issues, periods, or accounts to examine.
1. Reporting losses year after year
This is the classic trigger. A business that reports losses for three, four, five consecutive years while the owner keeps paying rent invites an obvious question: where is the money coming from? The CRA starts to suspect the business is a hobby, or that income is being under-reported. Startup years get some grace, but a string of losses with no credible turnaround story is one of the most reliable ways to get a letter.
2. Expenses that look nothing like your industry
The CRA compares your margins to businesses like yours. If restaurants in your area run 8 to 12 percent profit and yours runs 2 percent with unusually high “consulting” or “miscellaneous” expenses, the risk score climbs. Every deduction needs a business purpose and a receipt to match.
3. Cash-heavy operations with fuzzy records
Construction, restaurants, auto repair, retail, and personal services get extra attention because cash is harder to trace. None of that means cash sales are illegal, but deposit records have to reconcile with reported revenue. When bank deposits exceed reported income, the CRA uses a net worth assessment: it reconstructs what your income must have been from your assets and lifestyle, and the difference becomes taxable income unless you can explain it.
4. GST/HST input tax credits out of line with sales
Regularly claiming large input tax credits relative to your sales tells the CRA’s system that something is off. Common problems include claiming ITCs on purchases that were never paid for or mixing personal purchases into business filings. GST/HST programs also use random selection, so even clean files get examined sometimes. Sloppy ITC paperwork turns a routine review into a painful one.
5. Income that does not match the slips the CRA already has
Every T4, T5, T4A, and T3 issued in your name or your corporation’s name is already sitting in the CRA’s computers before your return is assessed. Report less income than those slips show and the mismatch is flagged automatically. This catches more people than any fancy risk model, and it is entirely avoidable. Reconcile every slip you receive against your return before you file.
6. Late, amended, or missing filings
A history of late returns, amended T2s, or ignored filing requirements signals poor compliance, and the CRA’s selection models factor it in. The penalties alone are reason enough to fix this: a late return with tax owing draws 5 percent of the unpaid tax plus 1 percent per complete month, up to 12 months (17 percent maximum). A corporation late in any of the previous three years faces a repeat penalty of 10 percent plus 2 percent per month, up to 20 months (50 percent maximum). Interest compounds daily on top. Repeated non-filing can also trigger a demand to file and, in serious cases, gross negligence penalties of up to 50 percent of the unpaid tax.
7. Shareholder loans that never get repaid
Owner-managers who pull money from the corporation through the shareholder loan account and leave it there are playing with one of the CRA’s favourite audit items. Amounts not repaid within one year after the corporation’s year end generally become deemed taxable income to the shareholder. A growing debit balance year after year is practically a signpost for the auditor.
8. Related-party and non-arm’s-length transactions
Payments to family members, intercompany charges, and management fees to related entities all attract scrutiny, especially when the amounts look generous for the work done. Salaries to a spouse or children must be reasonable for the services actually performed, with records to back it up.
9. Living above your reported income
The CRA compares your lifestyle to your reported income. A modest T1 paired with a new luxury vehicle, significant renovations, and private school tuition raises the net worth question: how is this funded? Large personal asset purchases should be explainable by reported income, inheritances, gifts, or legitimate loans. If they are not, expect the auditor to want documentation.
What to do if the CRA comes calling
First, read the letter carefully. A processing review, a matching letter, and a full audit are different things with different scopes, and your response strategy should match. An audit notice will state what is being examined, which periods, what documents are needed, and who your auditor is. Desk audits are handled by mail; field audits may take place at your office or your accountant’s.
You have the right to be treated professionally, to have complete and clear information about what is required, to be represented by someone you choose, and to disagree with the findings. If the audit ends with adjustments, you will receive a proposal letter (you generally have 30 days to respond) and then a Notice of Reassessment. If you disagree with that, you can file a notice of objection, usually within 90 days of the assessment date.
The boring defences that actually work
Most audit pain comes from preventable weaknesses. Keep books that reconcile to your bank statements, keep every receipt and invoice, and keep business records for at least six years from the end of the tax year. File on time, even if you cannot pay in full; unfiled returns erase the reassessment clock (the CRA normally has three years from the initial assessment to reassess a small corporation, but there is no time limit for unfiled returns or misrepresentation). Reconcile your slips before filing, separate business and personal money, and have a qualified professional review your return before it goes in.
Prevention beats representation. The cost of clean monthly bookkeeping is a fraction of what a single audit defence costs in professional fees, interest, and your own time.
Want an audit-ready set of books?
Audits rarely target clean files, and clean files start with monthly bookkeeping that reconciles to your bank. Our team is led by qualified professionals with more than 75 years of combined experience, PwC-trained, with CFO-level experience at world-leading multinationals. See our bookkeeping and tax services and straightforward pricing: monthly bookkeeping from $199, catch-up work at $45/hr, year-end corporate returns from $449 (CAD, HST extra). Book a free consultation and we will tell you honestly whether your books would survive an audit.
