What are add-backs on a self-employed mortgage application? (Canada)

In Canada, an "add-back" is a business expense that a lender adds back to your tax-return income when it works out what you earn for a mortgage. An add-back is usually an expense that did not take cash out of the business that year. Whether a lender adds anything back, and what, varies from lender to lender: there is no published rule, and many lenders add back little or nothing. What you deduct on your return is a decision for your accountant; our part is to show how lenders generally read the result, subject to lender approval.

Why add-backs exist

Lenders generally look at self-employed income over two years of tax returns, confirmed by Notices of Assessment. Our page on why lenders want two years of NOAs explains why. Legitimate business expenses lower your taxable income, and they also lower the income a lender sees. Our page on how lenders count self-employed income covers that write-off problem and the two-year average.

Some expenses on a return are accounting entries rather than money that left the business during the year. Some lenders are therefore willing to add part of those entries back. An add-back is no more than a lender's judgement that part of what you deducted does not reduce your ability to pay a mortgage.

Expenses some lenders add back

The items below are examples that commonly come up, not a list any lender is bound by. Each lender has its own policy, and an item one lender adds back another may ignore.

• Depreciation (capital cost allowance on your return): a non-cash deduction for equipment or vehicles bought in earlier years. Some lenders add part or all of the depreciation back.
• Business-use-of-home expenses: some lenders add back the share of home costs you deducted. You pay those costs as a homeowner anyway, and the mortgage application already counts them.
• One-time costs that will not repeat, where you can document them. Some lenders consider one-time costs case by case.

Add-backs are generally applied to income that is already on your return. Add-backs do not turn income that was never reported into income a lender will count. Where a lender averages two years, it generally applies the same add-backs to each year before averaging.

Some lenders and insurers also have programs that look at the business more broadly. Alternative lenders may use other evidence, such as bank statements, usually at a higher cost.

A worked example of three lender readings

Illustrative, not a quote. Your return shows $70,000 of net business income, after deducting $9,000 of capital cost allowance and $4,000 of business-use-of-home expenses.

1. A lender that adds nothing back counts $70,000.
2. A lender that adds back depreciation only: $70,000 + $9,000 = $79,000.
3. A lender that adds back both: $70,000 + $9,000 + $4,000 = $83,000.

For an insured mortgage, housing costs can be up to 39% of gross income, and all debts up to 44%, both calculated at the qualifying rate (source: CMHC, checked October 2026). On the third reading, the extra $13,000 of counted income would allow up to 39% × $13,000 = $5,070 a year more in housing costs, about $420 a month. Your other debts are still tested against the 44% limit. Whether any lender reads your return this way is subject to lender approval.

What to ask about add-backs

• Ask the lender, through us, which deductions it adds back, and whether it does so before or after averaging two years.
• Ask your accountant to show you where each expense sits on your return, so the figures a lender asks about are easy to find.
• Ask whether the lender also wants financial statements for the business.

What to do next

Try income as lenders see it for a document list and the questions to take to your accountant. The tool's results are estimates only, not an offer or advice. Or use our call-back form, and we will tell you how the lenders we work with generally read returns like yours.