CRA late-filing penalty calculator

The two penalty tracks, exactly

The basic penalty applies the first time a return with a balance owing goes in late: 5% of the tax that was unpaid on the due date, plus 1% of that same amount for each complete month the return is late, capped at 12 months. Fully aged, that is 17% of the balance. The repeat penalty applies where the CRA issued a demand to file and assessed a late-filing penalty in any of the three prior years: 10% plus 2% per complete month, capped at 20 months — fully aged, 50% of the balance. Both tracks are computed on the unpaid tax, which is what makes the next section the most useful thing on this page.

Why filing beats paying, if you can only do one

The penalty is a percentage of the tax unpaid at the due date — but it only exists at all if the return is late. File on time with nothing paid and there is no late-filing penalty, only interest. File four months late on the same balance and the penalty in the calculator above appears in full. The practical rule for anyone short of cash in April: file anyway. The return and the payment are separate acts, and the expensive one to delay is the return. The CRA also offers payment arrangements for the balance itself.

What this calculator leaves out, on purpose

Arrears interest — charged daily, compounded, at a prescribed rate the CRA resets every quarter — accrues on the unpaid tax and on the penalty itself. Because the rate moves quarter by quarter and compounds daily, any single-number estimate would be false precision; what matters is its direction: the total grows every day until both the return and the balance are dealt with. A refund year is the mirror image — no balance owing means no late-filing penalty at all, just your own money waiting.

If more than one year is late

Multi-year catch-ups are one project, not several: slips retrieved from CRA records, years prepared oldest-first so carry-forwards flow, everything filed with the total known in advance. Where the penalties trace to events genuinely beyond your control — illness, disaster, CRA delay — the taxpayer relief process can cancel penalties and interest inside its strict ten-year window. And where years are late but the CRA has not yet asked, the Voluntary Disclosures Program may apply. The order of operations matters more than any single form.