Filing Multiple Years of Tax Returns
How to catch up on years of unfiled Canadian tax returns, step by step.
The short version
- File the missing years as soon as you can. If you're owed money, the oldest refunds expire first; if you owe, penalties and interest grow every month.
- Get your slips for past years from CRA My Account, or ask CRA for them. Tax software can file 2018 to 2025 online; older years go on paper.
- CRA can send a demand to file, or estimate your income and assess you without a return. Its estimate is rarely in your favour.
- Income CRA doesn't know about? An unprompted voluntary disclosure can bring 100% penalty relief and 75% interest relief. Get advice before you apply.
- Benefits for you and your family stop until the returns are in.
How to File Years of Unfiled Taxes in Canada
Unfiled returns are like a pile of laundry. The longer it sits, the worse it gets, and the more you avoid the room it's in. Most people who are years behind aren't hiding anything. Life happened: a divorce, a business that folded, a parent who got sick. The fix is less painful than the dread, and for many people it ends with a cheque.
Step 1: Work Out Which Years Are Missing
CRA My Account shows which years were filed and assessed. If you can't get in, call CRA and ask which returns are outstanding. Write the list down. Then for each year, note what you think happened: refund, balance, or no idea.
Not sure some of those years even needed a return? See do I have to file taxes in Canada. Often the answer is “not legally, but you're missing benefits.”
Step 2: Get the Slips
- My Account keeps slips CRA received for past years: T4, T4A, T5, T3, RRSP receipts and more. See T4 slip explained if the boxes are a mystery.
- CRA by phone can send copies if you can't get online.
- Banks and employers can reissue slips or year-end statements.
- Self-employed years: rebuild income from bank deposits and invoices, and expenses from statements and receipts. Keep your working papers.
Can't get a slip at all? Estimate from pay stubs or statements and include a note; see missing T4.
Step 3: File, Oldest First If You're Owed Money
Certified tax software can NETFILE returns for 2018 to 2025 during the current filing season. Returns for 2017 and earlier are filed on paper, using the forms for that year. If you expect refunds, file the oldest years first: CRA generally only refunds the last ten calendar years, so those are the ones about to expire. If you owe, file every year promptly, because the late-filing penalty and interest grow monthly. Details on filing taxes late.
Each year's return can change the next one: carryforward tuition, capital losses, RRSP room and business losses all flow forward. Doing the years in order keeps those numbers right. How far back each kind of claim reaches is on how far back can you file taxes.
Several years behind and not sure where to start?
Tell the assistant which years are missing and roughly what happened in each. It tells you the order to file in, what each year is likely worth, and which years to watch for penalties.
Step 4: Deal With What You Owe
Pay what you can, then set up a payment arrangement for the rest. Interest keeps running, but collection action usually doesn't start while you keep to the plan. See paying CRA late.
If CRA Has Already Contacted You
A demand to file has a deadline. Meet it, even if the return isn't perfect; you can change it later. Ignore it and CRA can raise an arbitrary assessment: it estimates your income from slips and other information and assesses tax on that. It won't include your deductions, so the bill is usually too high. If you get one, file the real return; CRA generally replaces its estimate with your numbers. In serious, repeated cases, failing to file after a demand can lead to prosecution.
Income CRA Doesn't Know About
If the missing years include income that never appeared on a slip (cash work, a side business, foreign accounts), consider the Voluntary Disclosures Program before CRA contacts you. Under the program in effect since October 1, 2025, an unprompted disclosure can get 100% penalty relief and 75% interest relief, and no referral for prosecution. A prompted one (CRA already had information about you) can still get up to 100% penalty relief and 25% interest relief. You still pay the tax. Relief generally covers up to ten years back. A free pre-disclosure discussion with CRA is available, but most people should talk to a tax professional first. The details are on the Voluntary Disclosures Program.
What You Get Back by Filing
- Refunds of tax withheld from jobs, pensions and RRSP withdrawals.
- Benefits recalculated from your returns, such as the Canada Child Benefit and the Canada Groceries and Essentials Benefit. Limits apply to how far back some can be paid.
- RRSP room recorded for every year of earned income.
- A clean record, which matters for mortgages, which ask for notices of assessment.
The amounts are in our guides to tax credits and the income tax calculator estimates each year. Once the returns are ready, Return Check reviews each one before you send it, so the catch-up doesn't create a new round of reassessments.
Unfiled Returns Questions
What happens if I have not filed taxes for several years in Canada?
If you owe tax, late-filing penalties and daily interest build up for each year. If you are owed refunds, they expire after about ten years. CRA can also demand returns or assess you on its own estimate of your income, and benefit payments stop until you file.
How do I file old tax returns in Canada?
Get your slips for each year from CRA My Account or from CRA by phone, then file each year. Certified software can file 2018 to 2025 online; earlier years are filed on paper.
Should I file the oldest returns first?
If you expect refunds, yes, because refunds are generally limited to the last ten calendar years. Filing in order also keeps carryforward amounts such as tuition, losses and RRSP room correct.
What is an arbitrary assessment?
When you do not file after a demand, CRA can estimate your income and assess tax without your return. The estimate usually ignores your deductions and credits; filing your actual return generally replaces it.
Can I avoid penalties on unfiled returns?
Possibly. An unprompted application to the Voluntary Disclosures Program can get 100% penalty relief and 75% interest relief. Taxpayer relief may also cancel penalties for circumstances beyond your control.
Sources: CRA, The Voluntary Disclosures Program: your second chance; NETFILE; Tax refunds; Interest and penalties on late taxes. Checked October 2026. How far back benefits can be paid differs by program; we haven't listed each limit.
Last reviewed October 5, 2026 against CRA and Government of Canada sources. How we check our facts.