How to File Multiple Years of Canadian Income Tax Returns

Tax season is approaching, and soon more than 30 million Canadians will be filing returns. While most people file annually, a Carleton University paper estimates as many as 12% of Canadians do not file. Missing returns not only forfeits refunds but also blocks access to tax-free and refundable federal and some provincial benefits. Everyone aged 18 and older should file a return—even with no income—to receive credits and benefits like the federal GST/HST credit, the Canada Dental Benefit and the new Canada Dental Care Plan rolling out in 2024, and, in certain provinces, the Climate Action Incentive to offset carbon costs at the pump.

“Even if you’ve fallen behind, you may have missed credits and benefits, but that doesn’t necessarily mean you owe the government a lot of money,” says Andrew Wall, a CPA and managing partner at CPA4IT Professional Corporation. Still, if the Canada Revenue Agency (CRA) issues a formal notice to file, you may need to prepare multiple years of returns at once. That can be confusing, time-consuming—and costly if penalties and interest apply. Starting in 2024, interest costs can be high: 10% for the first quarter in some cases. The bottom line: file on time when possible, and if you owe, pay as soon as you can. Penalties and interest can grow into a larger financial burden than the original taxes.

Why some Canadians don’t file on time

There are efficient ways to file—using tax software or paying a professional—but many still avoid the task. “The most common reason is the ostrich approach,” Wall says. People ignore letters and notices, hoping the problem will go away. That avoidance often intensifies when CRA sends demand-to-file notices threatening account freezes or legal action. Many delay until the situation escalates.

People frequently fall behind for multiple years, not just one. Self-employed individuals and small business owners are more likely to miss filings because they manage different income streams and complex deductions compared with employees who typically only need a T4. Self-employed filers also pay Canada Pension Plan (CPP) contributions on net business income, which raises filing complexity and potential balances owing.

If you have a balance due of $3,000 or more, CRA typically places you in a profile that requires quarterly instalment payments the following year. The same risk applies if you receive significant investment income, pensions, or taxable support payments that don’t have withholding applied.

What is the penalty for filing taxes late in Canada?

You can request adjustments for errors or omissions up to ten years from the end of the tax year, which can generate refunds or recover missed refundable credits. In limited circumstances, you may qualify for relief from penalties and interest.

Deliberate failure to report income or filing false records is tax evasion, a criminal offence that can carry severe penalties—up to 200% of taxes owed—plus interest and potential jail time. Gross negligence—turning a blind eye to filing obligations—is not a criminal offence but can trigger a substantial administrative penalty: 50% of the taxes owing plus interest.

How does interest on taxes owed work?

CRA charges compound daily interest on outstanding balances. If you miss the April 30 deadline for the most recent tax year, interest begins to accrue on May 1. The interest rate is based on CRA’s prescribed rate, reassessed quarterly, so it can change over time.

Basic late-filing penalty rules: if you file late and owe tax, you’ll pay a penalty equal to 5% of the balance owing plus 1% for each full month the return is late, up to 12 months. If you are filing late for amounts owing from the previous three years after CRA has formally requested a return, the penalty increases to 10% of the balance plus 2% for each full month late, up to 20 months.

Because interest compounds daily, older debts can carry substantial interest. When repaying multiple years of tax debt, it can sometimes make sense to prioritize older balances that have already accumulated compounded interest—run the numbers or get professional advice.

How to file taxes for previous years

When catching up on multiple years, Wall recommends starting with the year after you last filed and moving forward. For example, if your last filed year was 2017, prepare 2018, then 2019, and so on. Many advisers also suggest beginning with the previous three years, since that represents the typical assessment window for many taxpayers.

Documentation can be a stumbling block. Sole proprietors and freelancers should keep bank statements, credit card records and receipts for at least seven years—the current tax year plus six prior years—to support income and expense claims. If you’ve closed accounts or lost receipts, it can be difficult to recreate the records CRA requires.

For simple employees with only a T4 and no special claims, documentation needs are minimal. But if you claim childcare, medical, moving expenses, donations or tuition, you must keep readable, reproducible proof. CRA increasingly accepts electronic copies or scans, but credit card or bank statements alone are not sufficient evidence for certain claims—you still need original receipts or saved electronic copies of those receipts.

Filing multiple late returns can raise your audit risk, especially if you are self-employed. If audited and you cannot substantiate claims, refunds can transform into balances owing, and late-filing or gross negligence penalties may be applied.

Can you avoid interest on tax balances spanning multiple years?

Penalties and interest arise when returns are filed late and taxes are unpaid, or when CRA disagrees with claims after an audit. In some cases you can request relief under the Taxpayer Relief Program for extraordinary circumstances—serious illness, a death in the family, or other situations that prevented filing. File Form RC4288 to request cancellation or waiver of penalties and interest, and include detailed supporting records.

Another option is the Voluntary Disclosure Program: if you voluntarily come forward to correct past non-compliance before CRA has contacted you, you may qualify for partial relief. You will still pay the taxes owed and likely some interest, but penalties may be waived in whole or in part at CRA’s discretion.

Where relief is not available, the CRA generally offers payment arrangements. “Deal with the CRA and set up a payment plan,” Wall advises. They will often arrange manageable payments rather than immediately pursue collections. Ignoring notices, however, increases the risk of collections, account seizures or legal action.

Should you prepay taxes to avoid future multi-year issues?

You can prepay taxes by making instalments or deposits to your tax account. Prepayments that create a credit balance typically roll forward to the next year. However, Wall cautions that prepaying may not be the best use of funds if those dollars could earn a higher return elsewhere—such as in a GIC, a high-interest savings account, or a tax-free savings account (TFSA)—and then be withdrawn when taxes are due. Using a TFSA can preserve tax-free investment growth and still allow access to funds when needed, though recontribution timing rules must be observed.

Why you should file even if you don’t owe money

Filing matters even when you expect no tax liability because many refundable or tax-free benefits depend on annual returns: the Canada Child Benefit, GST/HST credit, Canada Dental Benefit and other provincial supports. Non-refundable credits, such as the Disability Tax Credit, require filing to claim. Investors should file to report capital losses that can offset gains in prior or future years. Filing is also necessary to report dispositions of a principal residence in certain cases and to qualify for Old Age Security and other retirement-related benefits. Remember to report worldwide income in Canadian dollars and to disclose offshore investments when required.

If you face a multi-year filing situation, consider engaging an experienced tax professional who can prepare late returns, negotiate relief, and help set up repayment plans. Addressing the issue sooner reduces stress and the likelihood of mounting penalties and interest.