One support cheque, two very different tax treatments

The situation

The letter from the tax authority arrived nine months after Adnan and Tariq's separation agreement had been signed, and it did not ask a question. It stated a position: the monthly payment Adnan had been sending Tariq since the split was, for tax purposes, entirely spousal support, meaning Adnan could deduct all of it, and meaning Tariq should have been reporting the full amount as income for the past three tax years. Tariq had not been doing that. Neither, as it turned out, had anyone worked out what portion of the payment was actually meant to be spousal support and what portion was child support for their two children.

Adnan ran a veterinary practice through a corporation, drew a mix of salary and dividends, and had structured the support payment as one round number that felt fair when he and Tariq worked it out between themselves, without lawyers, at Tariq's kitchen table. Tariq, a sales director, had been reporting a smaller amount as income, on the understanding that most of the payment was for the children and therefore not taxable to him and not deductible to Adnan. That understanding had never been written down anywhere the tax authority could see.

The dispute in front of Adnan now covered three years of payments, and the amount in question, once the corresponding deductions and inclusions on both sides were added up, sat well into six figures. Adnan's accountant, Minh, had claimed the full deduction each year on the assumption that the whole payment was spousal support, because that was what made the numbers work best on his return. Nobody had gone back to the separation agreement, largely because the separation agreement did not actually specify the split.

Adnan came to us not entirely sure whose fault this was, only that he now faced a reassessment that would erase several years of deductions he had already relied on, plus interest. He wanted to know whether the payments could still be treated the way he and Tariq had always meant them, or whether the label the tax authority had chosen was simply going to stand.

What the law actually said

Under the Income Tax Act, support payments are only deductible to the payer and taxable to the recipient when they qualify as spousal support, and a single payment that mixes child support with spousal support in one undifferentiated amount is treated, by default, as entirely child support. Child support is neither deductible nor taxable. That default rule exists precisely to stop the kind of informal blending Adnan and Tariq had done, where a couple agrees to one number without saying what it is for, and the tax result ends up depending on which side is more motivated to argue for a particular label.

This meant the tax authority's opening position, that the whole payment was deductible spousal support, was actually wrong on the law, not just aggressive. If the payment was genuinely undifferentiated, the default rule pointed the other way entirely, toward treating it as non-deductible child support, which would have been worse for Adnan, not better. The real question was whether the payment could be shown to have a specific, identifiable spousal support component, separate from the child support component, because only that specific component could be deducted.

That distinction mattered enormously for the dollar amount in dispute. If none of the payment could be shown to be spousal support, Adnan stood to lose every deduction he had claimed across three years, with interest running the whole time. If some identifiable portion could be shown to be spousal support, only that portion's tax treatment was actually correct, and the rest of what he had deducted was not.

We also had to account for what Tariq had been reporting, since a consistent position mattered to the tax authority's assessment of both files, even though Tariq's return was not ours to defend. The separation agreement itself, being silent on the split, was not going to resolve this. We needed a source that showed what the parties had actually intended when they set the number, something contemporaneous with the agreement rather than a reconstruction built after the fact for the reassessment.

What we did

1. Pulled every piece of correspondence around the separation agreement's drafting, not just the signed document itself, because the agreement's silence on the split meant we needed evidence of intention from somewhere else. Email and text exchanges from the weeks the agreement was negotiated were the most likely place to find it, since records made before any dispute existed carry real weight, and neither side had a reason to shade them at the time. That request produced several months of exchanges to work through.
2. Found the actual split in an ordinary email nobody had thought to check, a message from Tariq to Adnan sent two weeks before signing that laid out, in plain language, a rough division between an amount for 'the kids' costs' and an amount described as 'help while I get back on my feet.' It was not drafted as a legal document, but it was dated, specific, and consistent with the total.
3. Cross-referenced that split against three years of actual bank records and payment history to confirm the stated ratio had held steady month over month, because a one-time mention in an email carries far more weight if the payments themselves reflect it consistently, rather than the ratio drifting over time or looking invented only after the reassessment arrived. The match, once laid out month by month, was close enough to be convincing on its own.
4. Prepared a written submission to the tax authority arguing that the payment, properly understood, had an identifiable spousal support component supported by contemporaneous evidence, and that only that component should be treated as deductible, with the balance correctly treated as non-deductible child support under the default rule. Framing the argument around the statutory default, rather than simply disputing the number, gave the reviewing officer a legal basis to accept a lower figure without conceding the file entirely.
5. Recalculated Adnan's exposure line by line under the corrected split rather than accepting the tax authority's original all-or-nothing position, applying the identified spousal share to each of the three years separately instead of as one blended total. The result was a materially lower reassessment than either the authority's opening letter or a worst-case reading of the default rule would have produced, and a number Adnan could actually plan around.
6. Negotiated the interest calculation down to the corrected principal rather than the amount originally assessed, since interest had been accruing on the larger, incorrect figure since the first year in question and would otherwise have kept compounding on a number we had already shown to be wrong. Recalculating it against the reduced principal meaningfully lowered the final bill on top of the underlying correction itself.
7. Drafted a short addendum to the separation agreement, signed by both Adnan and Tariq, that formally split the payment into stated child and spousal components going forward, so no future year would depend on an old email being found again. Putting the split in writing, with both signatures, gave both sides a document the tax authority could rely on without any further reconstruction.
8. Advised Minh, Adnan's accountant, on the corrected claim for current and future returns, walking through exactly which portion of the payment could be deducted and why, so the practice would not repeat the same undifferentiated deduction in a year still open to reassessment. That conversation closed the gap that had let the original error happen in the first place and gave Minh a clear rule to apply going forward rather than a guess.

The outcome

The tax authority accepted the corrected split, largely because the email was dated, specific, and matched the payment history closely enough that arguing against it would have been an uphill fight for them too. Adnan's reassessment came in at roughly a third of what the original letter had proposed, still a real cost, still three years of interest on the disallowed portion, but a fraction of what he had feared when the first letter arrived. Tariq's own filings needed correcting as well, once the split was established, so the income he had underreported for the spousal portion was brought current at the same time rather than left as a loose thread the tax authority could return to later.

He did not get to keep the full deduction he had originally claimed. That was not on the table once the payment's true composition was established, and we were honest with him about that from the first meeting. The child support portion was never going to be deductible, no matter how the case was argued, and pretending otherwise would have wasted time and legal fees on a position that could not hold. Adnan's accountant, Minh, had made a reasonable assumption years earlier, but it was an assumption rather than something checked against the agreement or against what Adnan and Tariq had actually intended, and that gap was what the reassessment ultimately exposed.

What changed the outcome was not a clever legal argument so much as an ordinary email that had been sitting in an inbox the whole time. Adnan later said the case taught him more about how support payments actually work for tax purposes than the year of informal arrangements with Tariq ever had. The addendum now governs future payments, and both sides report consistently, which is the arrangement that should have existed from the start. For a couple who had tried to keep things simple by not overthinking a single monthly number, the case was a reminder that simplicity on paper is not the same as clarity for tax purposes, and the two can come apart expensively if nobody checks.

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