Paid Too Much by Your Employer: Repay Gross or Net?

One month, the pay deposit is bigger than usual. Three months later, the employer notices and asks for the money back. Except that you never saw all of it: part of it went to tax and contributions before it ever reached your account. Do you hand back what you received, or what your employer paid out? The answer does not depend on your good faith. It depends on what caused the error.

The gap between what was paid out and what you received

Take a $60,000 salary in Quebec, and an overpayment of $2,000 gross.

Out of that $2,000, you did not receive $2,000. You received about $1,158. The missing $842 — 42% of the amount — went to deductions: federal tax, Quebec tax, QPP, Employment Insurance and QPIP.

Why 42%, when that salary is taxed at roughly 24% on average over the year? Because a dollar added to your salary is not taxed at the average rate, but at the marginal rate — the rate that hits the next dollar earned, and only that one. On $60,000 in Quebec, that marginal rate is about 36%. Add the three contributions taken off every dollar of salary and you land at 42%.

Here is where the money goes on that $60,000 salary, over a full year:

That mechanism, which we break down in our article on what separates gross pay from net pay, is what creates the overpayment question in the first place: your employer took $2,000 out of its accounts, you received $1,158, and the remaining $842 is already with the governments.

The CRA rule: net only if it was a system error

The Canada Revenue Agency separates two situations, and that distinction decides everything.

First case: a processing error. A box filled in wrong, payroll software going off the rails, an hourly rate keyed in twice. The CRA calls this a clerical, administrative or system error. In that case, and only in that case, the employer may elect to ask you for the net amount — that is, the gross minus the income tax, QPP and EI that were withheld. The $1,158, then, not the $2,000.

Second case: everything else. If the employer does not make that election, or does not meet the conditions for it, you have to repay the gross amount. The $2,000.

The important word here is elect. Net repayment is not a right you can demand: it is an option the tax rules open up to the employer. There is no form to fill in to use it, but the employer is the one who decides.

The conditions that have to be met for the net to apply

Four conditions have to hold at the same time.

1. The overpayment really did come from a clerical, administrative or system error.
2. The business is still actively operating.
3. The employer has not already issued a T4 slip showing your exact earnings, meaning earnings corrected for the overpayment.
4. The election is made no later than three years after the end of the year in which the salary was overpaid, and you have repaid the net amount or arranged to repay it.

If a single one of those conditions is missing, you are back to the gross.

When the gross applies and you repay, the employer has to issue an amended T4 slip: it reduces the employment income in box 14 by the amount of the overpayment, but leaves the contributions and the tax that were withheld exactly as they were. Your taxable income therefore drops by $2,000, and the tax already withheld on that amount comes back to you when you file your return. You do not lose the $842 — you get it back later, not right away.

The employer's own share, on the other hand, does not come back automatically: to recover its portion of QPP and EI, it has to apply using form PD24. It has four years after the end of the year for the pension plan, and three years for Employment Insurance.

Paid for a period you did not work: it is the gross

There is a third case, and it is the one that surprises people most. You were paid for a period you did not work: sick leave beyond what you were entitled to, parental leave, the weeks following a layoff, a signing bonus whose conditions were not ultimately met.

For the CRA, this is not a processing error. It is salary that really was paid, and that really was your income that year. The consequence has two parts:

• The T4 slip is not amended, even if you repay in the same year. The overpayment and the deductions stay on it.
• You deduct the amount yourself, on line 22900 of your income tax return, in the year you repaid it — not in the year you were paid.

For that, your employer has to give you a letter. It confirms the tax year in which the amount was included in your income, the reason for the overpayment, and the date and amount you repaid. Without that letter, you have nothing to support the deduction. Ask for it when you repay, not the following April.

If you have other adjustments to make to the tax withheld from your pay, form TD1 and its Quebec equivalent TP-1015.3 are the right tools — but they are not how an overpayment gets settled.

How long, and what can be taken off your pay?

There are two separate questions behind "how long", and they do not have the same answer.

On the tax side, the deadlines are written down: three years after the end of the year for the employer to elect the net amount, four years for it to recover its share of the pension plan and three years for its share of Employment Insurance. If the error is caught during the current year and before the slips are filed, the correction is far simpler: the employer adjusts it directly in payroll and in its remittances for the year, with no amended slip needed at all. That is why an overpayment flagged quickly costs everyone less paperwork.

On the labour law side, it is another story, and it has nothing to do with tax. In Quebec, the Act respecting labour standards governs what an employer may deduct from wages: it cannot simply help itself to your next pay to get its money back. Apart from deductions required by law, by a court judgment or by a collective agreement, a deduction in principle requires your written consent. An employer that wants to recover an overpayment therefore normally negotiates a repayment plan with you, or goes through the civil courts.

That part is a labour standards question, not a tax one: the CNESST is the body to ask, and it is also the one that will say within what time limit such a claim can still be made.

What to do, in practice

If your employer asks you to repay an overpayment:

1. Ask for the details in writing: which pay, which period, what gross amount, what net amount.
2. Ask which of the two rules applies: processing error, or salary paid for a period not worked? That answer is what decides whether you owe the net or the gross.
3. Do not repay the gross without the paperwork that goes with it. If it is the gross, insist on the amended T4 slip, or on the repayment letter in the case of a period not worked. That document is what lets you recover the tax.
4. Negotiate instalments. Nothing requires you to hand the money back in a single pay, and a deduction from wages does not happen without your written agreement.
5. Check the figure. Our Quebec net salary calculator gives you the exact deductions on a gross amount, which lets you verify the net your employer is asking you for.