Blog · Canadian tax review · August 2026
Deadlines can run on a notice nobody in your business ever read — and once they expire, the ordinary route to dispute an assessment may be gone.
If the CRA sends you an assessment you disagree with, the deadline to respond can matter just as much as whether you're right. Miss it and, in some cases, the ordinary route for challenging the assessment is gone. In others — especially for individuals — there may still be limited ways to fix the problem.
That distinction matters, because many people assume that if they never personally saw a CRA notice, or a request sat unanswered too long, there will always be a way to sort it out later. Sometimes there is. Sometimes there isn't.
For a GST/HST assessment, a business generally has 90 days to object — and if that's missed, up to one more year to ask for an extension. Miss both windows and, in many cases, the normal objection route is closed. Even if the assessment is wrong.
Here's the part that catches business owners off guard: those clocks can start running on a notice you never personally read.
Most businesses now get CRA correspondence through their CRA online account rather than on paper. An email alert goes out to whatever address is on file — which might be yours, your bookkeeper's, your accountant's, or someone who left the business three years ago. If your business has authorized someone to receive CRA correspondence through the online account, the CRA will often be treated as having validly delivered a notice once it's posted there and the alert goes out. The objection clock can run whether or not you ever see it.
The Tax Court decided a GST/HST case this spring that reads like a warning label.
A small company's bookkeeper handled everything with the CRA — filings, correspondence, the online account. She registered the company for CRA online mail using her own email address. When the CRA later assessed the company for several GST/HST periods, the notices were posted to the online account and the alerts went to her inbox.
The owner says he never saw them. Worse, the bookkeeper went quiet — he testified he tried to reach her for an extended period without success. By the time he learned about the assessments, both the 90-day objection window and the one-year extension window had expired.
The court was sympathetic but firm: the company had authorized the bookkeeper to manage its CRA account and receive its CRA mail. On those facts the notices were validly sent, and her failure to deal with them was not the CRA's problem. The application was dismissed — the company lost the ordinary right to challenge the assessments at all.
The judge himself flagged the bigger issue: a paper notice used to sit on your desk as a constant reminder. An email alert can slip past unnoticed until it's too late.
For many individuals, the more common problem isn't a missed objection deadline. It's a missed CRA request, a late response, a claim that never got filed, or penalties and interest that piled up because something wasn't dealt with in time.
Missing those deadlines is serious — but it isn't always the end of the road.
For personal tax matters, the CRA has some discretion to provide relief. Depending on the issue, that can include cancelling or waiving penalties and interest, allowing certain late refunds, or making an adjustment in your favour after the normal reassessment period has closed.
The outside limit is usually 10 years. In general terms, requests for penalty relief, late refunds, and certain favourable adjustments must relate to a tax year that ended within the last 10 calendar years, and interest relief is generally limited to interest that built up over the last 10 calendar years.
But be clear about what this is not: it's not a second objection system. The relief is discretionary, not automatic, and narrower than most people expect. If the real dispute is that the assessment itself is wrong, a relief request is no substitute for objecting on time. So if you missed a CRA document request, failed to claim something properly, filed late, or are facing penalties and interest, there may still be a path. If you're outside the objection deadlines and really trying to re-argue the assessment, the options are much thinner.
The lesson is less about technology than about control — and knowing which deadline you actually missed:
If the issue is an assessment, act immediately. Objection deadlines are strict, and once they expire the ordinary dispute route may be gone.
If the issue is a missed request or an unfiled personal claim, don't assume it's lost. There may still be discretionary relief available, particularly for individuals — but the 10-year window means older years can quietly fall away.
Know what email is on your CRA accounts. If you can't say whose inbox gets the alerts, that's the first thing to check.
Don't let one outside person be the only recipient. Delegating the bookkeeping is fine. Delegating the only copy of the mail is the risk.
Look at the account itself periodically. The alert emails are just pointers — the actual notices sit in the CRA online account. A quick look every month or so, by you or by us, catches problems while they're still fixable.
Treat CRA silence with suspicion, not relief. If you're expecting a refund or a response and hear nothing for months, it's worth confirming whether something has been posted to the account.
Elect paper mail where you can. Where the CRA still allows it, we encourage clients to choose paper delivery — or paper alongside online — so a notice lands somewhere it will actually be seen.
We'll be direct about our view as a firm: we disagree with the CRA's shift to electronic mail as the default.
Whatever the stated goals, the practical effect is one-sided. When a notice goes unseen, the deadlines still run, the assessment stands, and the penalties and interest keep building — all of which works out in the government's favour. A system where the taxpayer bears the full cost of a missed email looks to us less like modernization and more like a revenue-generating one. Cases like the one above are the predictable result.
Until that changes, our advice is simple: where the option exists, elect paper mail, and treat the online account as something to be actively watched — not a mailbox you can trust to flag itself.
The strict-deadline story above comes from a GST/HST case. Income tax has comparable objection deadlines, but the details aren't identical, and missing a deadline doesn't always mean the story is over — there can still be arguments about whether a notice was properly sent or whether the person receiving it was actually authorized. But once formal objection rights have expired, whatever remains is usually narrower, discretionary, and very fact-specific. And possible relief is not guaranteed relief — the CRA considering a late request doesn't mean granting it.
An assessment you disagree with is usually a manageable problem — if you see it in time. A business can be bound by a notice that nobody in management ever read, so long as it was routed through an authorized online account. And while individuals often have more room to fix a missed request or late claim, that room generally runs out at 10 years.
Know where your CRA mail is going, know which deadline applies, and don't assume silence means nothing is happening. And where you can still choose paper mail, choose it. If you're not sure on any of those, get in touch — sorting it out takes far less time than living with an assessment you never got to dispute.