Most Canadians have a healthy respect — and a fair amount of anxiety — when it comes to the Canada Revenue Agency. The good news is that the vast majority of CRA interactions are routine, and almost all of them are manageable when you understand the process and respond on time. As a CPA, I spend a meaningful part of my practice helping clients navigate exactly these situations. Below is a plain-language walkthrough of five compliance topics every taxpayer and business owner should understand: what to do if you’re audited, how the Voluntary Disclosures Program works, the filing mistakes that most often trigger CRA review, the penalties for filing late, and how to respond when a Notice of Reassessment lands in your mailbox.

What to Do If You Get Audited

First, take a breath. An audit is not an accusation of fraud. The CRA audits returns for many reasons — random selection, industry benchmarking, unusual ratios on a return, or information that doesn’t match third-party data such as T4s and T5s. A review or audit simply means the CRA wants to verify that what you reported is supported by your records.

When you receive an audit letter, note the auditor’s name, contact information, the tax years under review, and exactly what is being examined. Audits range from a narrow request for a single receipt to a comprehensive review of several years of books and records. Read the scope carefully so you respond to what was actually asked, and nothing more.

A few principles serve clients well. Respond by the deadlines in the letter, and if you need more time, ask for it in writing before the deadline passes — auditors are generally accommodating when you communicate proactively. Provide complete, organized documentation, but only for what has been requested. Volunteering extra material can inadvertently widen the scope of the audit. Keep your answers factual and avoid speculation; if you don’t know something, say you’ll confirm and follow up.

This is also the point at which professional representation pays for itself. You are entitled to have a CPA or tax advisor deal with the CRA on your behalf by filing an authorization (the CRA’s representative authorization through your My Account or My Business Account). A representative can frame your records appropriately, manage communication, and keep the process from spiralling. If the auditor proposes adjustments you disagree with, you usually have an opportunity to respond before the reassessment is finalized — use it, with supporting documentation.

Throughout, keep the relationship professional and cooperative. Auditors have significant discretion, and a taxpayer who is organized, responsive, and respectful tends to have a smoother experience than one who is combative or evasive.

The Voluntary Disclosures Program: Fixing Mistakes Before the CRA Finds Them

If you’ve realized that a past return was incomplete or incorrect — unreported income, a missed foreign-asset filing (Form T1135), unfiled GST/HST returns, or similar issues — the Voluntary Disclosures Program (VDP) can be one of the most valuable tools available. The program lets taxpayers proactively correct errors or omissions, and when an application is accepted, it can provide relief from penalties and from the prospect of prosecution, along with partial relief from interest.

The VDP was significantly overhauled effective October 1, 2025, under Information Circular IC00-1R7 and GST/HST Memorandum 16-5-1, and the changes are generally taxpayer-friendly. The old “General” and “Limited” programs were eliminated. Relief now turns on whether a disclosure is unprompted or prompted. An unprompted disclosure — one made before the CRA has contacted you about the issue — qualifies for the more generous “general relief” tier, which offers full penalty relief and relief of 75 percent of the interest. A prompted disclosure — made after the CRA has reached out about potential non-compliance — falls under “partial relief,” which still provides up to full penalty relief but only 25 percent interest relief.

A crucial change is that simply receiving a general reminder or an education letter from the CRA no longer automatically disqualifies you. Under the new rules, the program is more accessible, the gross revenue of a corporation is no longer a barrier, and the CRA may even consider a second application from the same taxpayer when the circumstances were beyond their control or relate to a genuinely different matter.

There are firm limits. To qualify, a disclosure must be voluntary, must be reasonably complete, must involve the potential application of a penalty, and must include information that is at least one year past due. You cannot use the VDP if a CRA audit or investigation is already underway on the matter, or if an outside enforcement body — such as the RCMP, a securities commission, or a provincial tax authority — is already investigating. The program also isn’t intended for situations that would simply produce a refund. Applications are made on Form RC199, which was streamlined as part of the 2025 changes. Because the relief depends heavily on getting the timing and completeness right, this is an area where speaking with a CPA before you file is genuinely worthwhile — coming forward properly, and early, is what unlocks the best outcome.

Common Filing Mistakes That Trigger CRA Review

Many reassessments and reviews are entirely avoidable. The single most common trigger is unreported income. The CRA receives copies of your T-slips — T4s for employment, T5s for investment income, T4As for various other income, and so on — directly from the issuers. When the amounts on your return don’t match the slips in the CRA’s system, an automated matching program flags the discrepancy. A forgotten T4 from a short-term job or a T5 from a brokerage account is one of the most frequent reasons a return gets adjusted.

This mistake carries a particular sting. The repeated failure to report income penalty applies when you fail to report an amount of income in the current year and also failed to report income in any of the three preceding years. The penalty can be substantial and, importantly, it is calculated on the unreported amount itself rather than on the additional tax — and it can apply even where little or no additional tax is ultimately owing. Accidental omissions are not a defence, which is why reconciling your return against every slip before filing is so important.

Other frequent triggers include claiming deductions or credits without proper documentation (charitable donations, medical expenses, and child-care costs are commonly reviewed), business or rental losses that recur year after year, home-office and vehicle expense claims that look disproportionate to reported income, large or unusual changes from one year to the next, and mismatches between spouses on shared claims. None of these claims is improper in itself — the issue is almost always documentation. The CRA’s post-assessment review programs routinely ask taxpayers to substantiate exactly these items, so keep your receipts and records organized and retain them for at least six years.

Deadlines and Penalties for Filing Late

The deadlines themselves are straightforward. For most individuals, the personal income tax return is due April 30 for the prior tax year, and any balance owing is also due that day. Self-employed individuals (and their spouses or common-law partners) have until June 15 to file, but any balance owing is still due April 30 — a distinction that catches many people off guard. Corporations must file within six months of their fiscal year-end, with payment timelines that depend on the corporation’s circumstances.

The late-filing penalty is where procrastination becomes expensive. If you file after the deadline and have a balance owing, the CRA charges a penalty of 5 percent of the unpaid balance, plus 1 percent of that balance for each full month the return is late, up to a maximum of 12 months. That works out to a maximum of 17 percent on a return filed a full year late. The penalty is steeper for repeat offenders: if you were charged a late-filing penalty in any of the three previous years and the CRA issued a formal demand to file, the penalty jumps to 10 percent of the balance owing plus 2 percent per month for up to 20 months — a maximum of 50 percent.

Two points are worth emphasizing. First, the late-filing penalty is calculated on tax owing, so if you don’t owe a balance, the penalty generally doesn’t apply — though there are excellent reasons to file on time anyway, including preserving benefit and credit payments such as the Canada Child Benefit and GST/HST credit. Second, separate from the penalty, the CRA charges compound daily interest on any unpaid balance starting the day after the payment due date, at the prescribed rate, which is set quarterly. Because interest compounds, an unpaid balance grows steadily the longer it sits.

The practical takeaway I give every client is simple: even if you can’t pay, file on time. Filing on time avoids the late-filing penalty entirely, leaving only interest on the unpaid amount — a far smaller problem. If you’re facing penalties or interest because of circumstances genuinely beyond your control, such as serious illness or a natural disaster, you can ask the CRA to cancel or waive them under the taxpayer relief provisions.

How to Respond to a Notice of Reassessment

A Notice of Reassessment means the CRA has reviewed a previously filed return and changed the result — perhaps adding income, denying a deduction, or recalculating tax, often months or even years after your original assessment. Receiving one is not unusual, and it is not the end of the conversation.

Start by reading the notice carefully to understand exactly what changed and why; the notice explains the adjustments. Then make a clear-eyed decision. Sometimes the CRA is simply right — you forgot a slip, and the math is correct — in which case the sensible course is to pay the balance and move on. Sometimes the reassessment reflects a straightforward error that a phone call to the CRA can resolve through a simple adjustment. And sometimes you genuinely disagree on a question of fact or law.

If you disagree, the most important number on the page is the deadline to file a Notice of Objection. For individuals (other than trusts) and graduated rate estates, the deadline is the later of one year after the return’s filing due date, or 90 days after the date on the Notice of Reassessment. For corporations and most other taxpayers, it is 90 days from the date of the reassessment. Filing an objection — online through My Account or My Business Account, or on Form T400A — preserves your right to appeal and sends the matter to the CRA’s Appeals Branch, an area independent of the auditor who made the reassessment.

If you miss the 90-day window, you are not necessarily out of options: you can apply for an extension of time, but the application must be made within one year after the original objection deadline and must explain why it was missed. Extensions are not automatic, so the safe course is always to object on time.

Two pieces of practical advice. First, an objection should set out the relevant facts and the reasons you believe the reassessment is wrong, supported by documentation — a well-organized objection is far more persuasive than a bare disagreement. Second, interest continues to accrue on a disputed balance while the objection is being reviewed. If there’s a real chance the CRA’s position will be upheld, it is often cheaper to pay the disputed amount now and receive a refund with interest if you win, rather than let interest compound for months. If the objection is unsuccessful, you retain the right to appeal to the Tax Court of Canada within 90 days of the CRA’s confirmation.

The Bottom Line

The thread running through all five of these topics is the same: the CRA’s processes are far less frightening when you understand them and respond promptly. File on time even when you can’t pay. Reconcile your return against every slip before you submit it. Keep your documentation organized. Watch the deadlines on any notice you receive. And when something has gone wrong — a missed filing, an unreported amount, a reassessment you don’t understand — deal with it early rather than hoping it disappears.

Most of these situations are entirely manageable, and many are resolved in the taxpayer’s favour with the right approach. If you’re facing an audit, considering a voluntary disclosure, or weighing whether to object to a reassessment, a brief conversation with your CPA before you act can make a meaningful difference to the outcome.

This article is for general information only and does not constitute tax or legal advice. Tax rules change frequently and individual circumstances vary; please consult a qualified professional about your specific situation.

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