- It's easy to assume these are the same issue, but CRA treats them separately.
- The deadline passes without a return submitted for that reporting period.
- Interest accrues on any unpaid net tax from the date it was due, at a prescribed rate that CRA sets and updates every quarter.
Life gets busy, bookkeeping falls behind, and suddenly an HST filing deadline has come and gone. If this has happened to you, you're not alone — but understanding exactly what CRA does when a return is late, and how the cost compounds the longer it sits unfiled, helps you decide how urgently to act.
This guide separates the two things that go wrong when you're late — the filing itself and the payment — and walks through what happens with each, plus how to get current if you're behind on more than one period.
Filing Late vs. Paying Late — Two Separate Problems
It's easy to assume these are the same issue, but CRA treats them separately. You can file a return on time and still owe money you haven't paid, and you can also miss the filing deadline entirely even if you eventually plan to pay in full. Both trigger consequences, and being late on both at once compounds the exposure — so even if you can't pay the full amount owing, filing the return on time still matters.
What Happens When You Miss a Filing Deadline
- The deadline passes without a return submitted for that reporting period.
- CRA's system flags the account as having an outstanding filing obligation.
- Interest and, depending on the circumstances, penalties begin accruing on any net tax owing for that period.
- If the pattern continues across multiple periods, CRA's response typically escalates — from automated reminders toward more direct collections or compliance contact.
None of these steps require CRA to prove wrongdoing; a missed deadline alone is enough to start the clock on interest.
Interest on Amounts Owing
Interest accrues on any unpaid net tax from the date it was due, at a prescribed rate that CRA sets and updates every quarter. This is the same prescribed rate that applies to unpaid income tax and other amounts owed to CRA — as of mid-2026 it stood at 7%, but this figure changes regularly, so verify the current rate before estimating what you owe rather than relying on a number from an old return or a general article.
Interest continues accruing on the outstanding balance until it's paid in full, which means the cost of delay compounds the longer a balance sits unaddressed.
Penalties for Late Filing
Beyond interest, CRA can assess a separate late-filing penalty on a return that's submitted after its due date, calculated based on the specifics of the return — how much is owed and how late it is. Because the exact penalty calculation depends on your particular facts, don't assume a flat percentage without checking your specific notice or getting professional advice; what matters most for your planning purposes is that the penalty is a real, additional cost layered on top of interest, not a substitute for it.
Repeat or Prolonged Non-Filing
A single late return, corrected promptly, is a very different situation from a pattern of missed filings stretching back multiple periods or years. Prolonged non-filing tends to draw more serious attention from CRA and can affect how any penalty relief request is viewed later. If you're behind on several returns, the priority is getting current as quickly as possible rather than waiting until you can pay everything at once — filing itself often has value independent of payment.
How to Get Back on Track
- File every outstanding return, even ones you can't pay in full yet, as soon as you're able to prepare them.
- Contact CRA about a payment arrangement for the balance owing rather than waiting for collections to reach out first.
- Ask about taxpayer relief if the lateness was caused by circumstances beyond your control — CRA has discretion to cancel or waive penalties and interest in appropriate cases, though relief is never automatic or guaranteed.
- Consider the Voluntary Disclosures Program if the situation involves more than a simple late return — for example, unreported amounts across multiple periods — since a qualifying disclosure can reduce penalty and interest exposure depending on whether it's made before or after CRA has already contacted you about the issue.
- Get organized going forward with a recurring reminder tied to your specific filing frequency, so a one-time lapse doesn't become a pattern.
Frequently asked questions
If I can't pay, should I still file the return on time?
Yes. Filing on time avoids one layer of consequence even if you can't pay immediately, and it puts you in a better position to negotiate a payment arrangement than if both the filing and the payment are outstanding.
Does CRA ever waive late-filing penalties and interest?
Yes, through the taxpayer relief provisions, but relief is discretionary — CRA decides case by case based on the reasons for the delay, and a request can be refused or only partially granted. There's no guarantee of relief simply because you ask.
I'm behind on several years of HST returns — where do I start?
Start by getting an accurate picture of exactly which periods are outstanding, then prioritize filing the returns even before you've resolved how you'll pay. If the situation involves errors or unreported amounts rather than just late filing, a tax professional can advise on whether a voluntary disclosure makes sense.
Will a late HST return trigger an audit?
Not automatically — a late return by itself is a filing issue, not necessarily a red flag for the kind of deeper review that leads to an audit. That said, patterns of late or inconsistent filing are one of several factors CRA's risk-based systems can consider.
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