CRA audit red flags for small business: what actually draws scrutiny

The honest answer first

The CRA does not publish the algorithm or the rules that select a return for review. Anyone telling you they know the exact formula is guessing. What follows instead is a list of patterns that accountants and bookkeepers widely recognize as commonly cited scrutiny magnets — not a leaked checklist, not a guarantee, and not a substitute for actually knowing what's in your own books. Some of these patterns are unavoidable (a startup loses money in year one; that's normal). The point isn't to avoid every item on this list. It's to make sure that if the CRA ever does ask, your records answer the question in five minutes instead of five weeks.

Patterns commonly cited as scrutiny-attracting

None of these guarantee a review, and none of them are illegal on their own. They're simply the categories that come up again and again when practitioners discuss what draws a closer look.

Recurring losses

A single loss year is unremarkable — plenty of real businesses have them. A business that reports a loss year after year, especially one that never seems to move toward profitability, is the kind of pattern that's widely cited as inviting questions about whether the activity is genuinely being carried on as a business.

Expenses out of line with income

Deductions that look disproportionate to reported revenue — a small business claiming expenses that swallow most or all of its income, or expense categories that jump sharply year over year without an obvious reason — are commonly flagged as the kind of mismatch that stands out.

100% vehicle claims with no logbook

Claiming that a vehicle is used 100% for business, with nothing to back it up, is a classic example practitioners point to. Vehicles almost always have some personal use, and without a logbook or comparable record showing business versus personal kilometres, a claim like that is hard to defend if it's ever questioned.

Home-office claims that overreach

The home-office deduction itself is completely legitimate — but it comes with real eligibility rules. The workspace generally needs to be your principal place of business, or used only to earn business income and used regularly and on an ongoing basis to meet clients or customers. The deductible amount also can't exceed your net business income before the deduction — it can't create or increase a loss, though unused amounts can be carried forward. Claims that stretch past those boundaries — a spare room used occasionally, or a deduction that conveniently zeroes out income — are what draw the "overreach" label, not the deduction itself. See our deduction guide for more on what's actually claimable.

Meals and entertainment over the 50% limit

Food, beverage, and entertainment expenses are deductible only up to 50% of the lesser of the amount actually spent and what's reasonable in the circumstances (there are limited exceptions — billed-back client costs, up to six staff social events a year, and certain remote-worksite meals). Claiming the full amount instead of the 50% portion is a mechanical error that's easy for a review to catch, because the math simply doesn't match the rule.

Cash-heavy industries

Businesses that deal heavily in cash — where transactions don't automatically generate a paper trail the way card payments do — are commonly cited as facing more scrutiny, simply because unreported income is easier to hide and harder to verify from the outside. The defence is the same as everywhere else on this list: consistent records of every transaction, cash included.

Unfiled or late returns

A pattern of missed or late filings — GST/HST, T2, T4s — signals disorganization at minimum, and it's one of the more visible things the CRA can see without opening a full review, since filing status is tracked automatically. Consistent on-time filing is one of the cheapest ways to look unremarkable.

Sloppy or missing records

This is the one that turns "you got selected" into "you have a problem." Tax records and supporting documents generally need to be kept for at least six years, even if you filed online or a form said you didn't need to attach them. A business that can produce receipts, invoices, and reconciled books on request has an annoying week. A business that can't is exposed on every claim it ever made, red-flagged or not.

The real thesis: you can't control selection, you can control survivability

Here's the thing nobody selling audit-proofing courses wants to say plainly: you don't control whether the CRA selects your return. Random sampling exists. Industry-wide sweeps exist. A supplier or client of yours getting reviewed can pull you into it. None of that is within your power to prevent, no matter how careful you are.

What you do control is what happens next. A business with clean, current, reconciled monthly books and organized receipts treats a CRA inquiry as paperwork — annoying, time-consuming, but not existential. A business with a shoebox of receipts and books that were last touched in March treats the same inquiry as a crisis, because now someone has to reconstruct a year of transactions under a deadline, while also proving every claim was legitimate.

The gap between those two businesses isn't luck or cleverness about which deductions to skip. It's whether the books were kept properly all year, every year. That's the whole game.

What "audit-ready" actually looks like

In practice, audit-ready means three unglamorous things happening consistently: every transaction categorized and reconciled monthly (not caught up in a scramble), every receipt kept and matched to its transaction, and returns filed on time so there's no separate compliance problem sitting on top of a records problem. None of this is exotic. It's what ongoing monthly bookkeeping is for — ours starts at $200/month, with HST filings included, precisely so this stays boring instead of becoming a scramble the one year it matters.

If your books have already fallen behind, that's fixable — see our guide on catching up when you're behind — but the cheapest version of audit-readiness is never falling behind in the first place.