One Late Interest Payment Nearly Cost a Family Its Income Split

The situation

Luc taught elementary school in Stratford, but for years he had also run a small incorporated consulting practice on the side, advising school boards and private tutoring companies on curriculum design. The corporation paid him a modest salary and, some years, a dividend on top of it. His wife Chantal worked as a millwright and earned considerably less, which put her in a lower tax bracket year after year.

Like many two-income families where one spouse earns more, Luc and Chantal wanted their investment savings taxed in Chantal's hands rather than his. Under the Income Tax Act, that is not automatic. If Luc simply gave or lent Chantal money to invest, the attribution rules would step in: any income the investments earned would be taxed back to Luc as though he had earned it himself, defeating the purpose entirely. There is one well-established way around this — a loan from the higher earner to the lower earner, charging interest at the Canada Revenue Agency's prescribed rate (a rate set quarterly and typically low), with the interest actually paid, in full, by January 30 of the following year, every single year the loan is outstanding. Miss that payment even once, and the exemption from attribution can be lost — not just for that year, but potentially for the rest of the loan's life.

On the advice of their accountant, Niloufar, the couple had set up exactly this kind of loan four years earlier: Luc lent Chantal roughly $310,000 from a dividend the corporation had paid him, Chantal invested it in a mutual fund portfolio, and each year she paid Luc interest at the prescribed rate that applied when the loan was made. For three years, the structure worked as intended and the investment income was reported on Chantal's return, taxed at her lower rate.

What the review found

The trouble started in the loan's fourth year. Niloufar had changed accounting software, and the reminder that normally prompted Chantal's interest payment never went out. Chantal transferred the interest to Luc on February 11 instead of by January 30 — twelve days late. Neither of them thought much of it at the time; the amount was correct, the payment cleared, and the couple kept reporting the investment income on Chantal's return as they always had.

Two years later, the couple's return was selected for a review. The CRA auditor flagged the loan and asked for the full payment history. Once the missed deadline surfaced, the auditor's position was direct: because interest for that year was not paid within the required window, the loan no longer qualified for the exception to the attribution rules from that point forward. The CRA proposed to attribute the investment income the loan had generated — not just for the late year, but for every year since — back onto Luc's return, where it would be taxed at his considerably higher rate. Across the two years under review plus a reassessment of the year the payment was missed, the CRA's position put roughly $142,000 of investment income back onto Luc's income, which would have added an estimated $54,000 in extra tax and arrears interest to the couple's bill.

The stakes were real, but so was the argument on the other side. Attribution for a late payment generally applies on a going-forward basis from the year the deadline was missed — it does not usually reach back and re-tax income the family had already correctly reported in the years before the slip. The auditor's initial proposal had blurred that line, and there was room to push back.

What we did

1. Reconstructed the full payment history. We pulled bank records for all four years of the loan to show precisely which interest payments had been made on time, and to isolate the single late payment as an anomaly rather than a pattern. Documentation this clean is unusual and it mattered — a family that can prove three years of on-time payments and one twelve-day slip is in a very different position than one that treated the deadline loosely.
2. Drew a clear line between past and future years. We prepared a written submission arguing that attribution, where it applies after a missed payment, operates prospectively — it taxes income earned after the failure differently, but does not reopen years where the family had already met every requirement. The two years already reported on Chantal's return, before the late payment occurred, had nothing wrong with them.
3. Conceded what could not be won. We did not argue that the late payment was harmless. It was not. Once the deadline was missed, the loan's exemption from attribution was gone going forward, and no amount of argument was going to restore it for that structure. Trying to fight that point would have spent credibility on a losing argument and delayed resolving the parts of the file that were actually defensible.
4. Negotiated directly with the CRA's appeals officer. With the payment records and the prospective-only argument in front of them, the file moved to a negotiated resolution rather than a formal objection and appeal, which would have taken considerably longer and cost more in professional fees than the amount ultimately at stake justified.
5. Set up a clean new loan to restart the strategy. Rather than trying to salvage the tainted loan, we advised Luc to repay it in full and issue Chantal a brand-new loan at the prescribed rate current at that time, with a calendar reminder system that did not depend on a single accountant's software. A fresh loan, properly documented and paid on schedule from day one, gave the family a clean structure going forward instead of one carrying a known defect.

The outcome

The CRA agreed to narrow its position. The two years reported before the missed payment stood as filed — no reassessment, no additional tax on income the family had already correctly split. But the CRA held its ground on the years after the missed deadline: that investment income was attributed back to Luc, as the rules allow once the on-time-payment condition has been broken. The final reassessment added roughly $18,500 in tax and arrears interest, well below the $54,000 the CRA had originally proposed, and about a third of the amount in dispute.

It was not a clean win, and it was not presented to the family as one. The old loan's tax advantage was gone for good — that income-splitting structure could not be repaired, only replaced. What the negotiation preserved was the principle that a single documented slip should not retroactively unwind years of properly reported income, and it converted what could have been a much larger reassessment into a manageable one. The new loan, set up correctly with automated reminders, has now run for two years without a missed payment, and the family is back to splitting investment income the way they originally intended.

Niloufar, to her credit, built the missed-deadline lesson into how she now manages every prescribed-rate loan file for her clients: a hard calendar reminder well ahead of January 30, not a system-generated one that depends on nothing going wrong.

What you can learn from this