HELOC or Refinance Interest on a Rental in Canada: Does CRA Care Which House Secures the Loan?

The address on your mortgage statement is the lender’s business. For tax, CRA follows the borrowed dollars to where they were spent, and that answer can surprise you in both directions.

I’m Arthur Zhao. Picture two owners at the bank, before anything is signed. One has built up equity in the home she lives in and needs a down payment for her first rental: the options on the table are a HELOC on her home or a separate mortgage on the new property. The other already owns a rental with equity in it and is thinking about refinancing it to fund a move into a bigger home of his own.

Both conversations circle the same question: which property should the loan sit on? That is the lender’s question, because the security is what the lender can collect from if payments stop. For tax, CRA asks something else entirely: what did the borrowed money actually buy? The two owners above end up on opposite sides of that answer, and neither of them gets there by picking a house to pledge.

So rather than sorting by loan product, this article takes the borrowing you have or are about to take and follows the dollars, one case at a time. It explains the rule, not your return; how it applies to your numbers is a conversation for your accountant.

The test in one sentence, and where it comes from

The rule starts in paragraph 20(1)(c) of the Income Tax Act, which allows a deduction for interest on “borrowed money used for the purpose of earning income from a business or property.” Notice what the text looks at: how the money was used. There is nothing in it about which asset was pledged.

According to CRA’s Income Tax Folio S3-F6-C1 (2024), whether that purpose test is met is a question of fact, and the test is the direct use of the borrowed money. The Folio quotes the Supreme Court of Canada on the point and draws two practical conclusions from it: the onus is on you “to trace or link the borrowed money to a specific eligible use,” and the use that counts is the money’s current use, not the original one. The Folio also notes that courts have accepted indirect use only in certain exceptional situations, so the direct use is what you should expect to be measured against.

Same tool, opposite answers

Case 1: A HELOC on your home that paid only for the rental

This is the cleanest version. CRA’s rental guide, T4036, says under Line 8710 – Interest and bank charges: “You can deduct the interest charge on money you borrow to buy or improve your rental property.” A line of credit secured by your home is still borrowed money, so if those exact dollars went to the rental purchase, the use is income-earning even though your home is the security. That last step is my application of the Folio’s direct use test to this fact pattern, not a sentence CRA prints about HELOCs specifically.

What makes or breaks Case 1 in practice is whether you can show the path. The Folio describes keeping borrowed funds separate from money from other sources, typically in separate accounts, a practice it calls cash damming, and says it “makes it easier for taxpayers to trace borrowed money to specific uses.” A draw that goes straight from the line to the purchase is easy to trace. A draw that lands in the chequing account where your pay also lands, sits there for weeks, and then leaves in pieces is much harder to defend.

Case 2: One line of credit used for both the rental and your life

Many people end up here: one line, some draws for the rental, some for a car or a renovation at home. The Folio covers this directly with a worked example (Example 10), and the numbers below are CRA’s, not mine.

The part people get wrong is the repayment. It feels sensible to say the $20,000 paid down the personal portion first, leaving the full $40,000 rental portion intact. The Folio says no: “The individual cannot allocate the repayment specifically to the ineligible portion of the borrowing.” In CRA’s view, a principal repayment on a single account used for both purposes reduces both portions, so the eligible share stays at 40% of whatever balance remains.

The Folio does allow a more flexible way of linking when borrowed money is mixed with other cash in one account, letting you choose which uses the borrowed money went to. It is explicit that this flexibility does not extend to repayments on a single borrowing account used for eligible and ineligible purposes.

Case 3: Refinancing the rental to pull cash for yourself

This is the reverse of Case 1, and CRA has answered it in its own words. According to CRA’s rental guide T4036 (2025 revision), a reader asked about this exact situation: they had refinanced a rented semi-detached house to increase the mortgage because they needed a down payment on their personal residence. CRA’s answer: “No. You are making personal use of the funds you got from refinancing your rental property.” The additional interest cannot be deducted in calculating rental income or loss.

Two details on the same page are worth knowing. First, T4036 says that if you refinance a rental to get money for a business or other investments, you may be able to claim that interest on Form 5000-D1 (carrying charges), not as a rental expense. Second, CRA’s answer is about the additional interest only. The interest on the original borrowing that bought the rental is a separate question, decided the same way: by what that money was used for.

Case 4: The money changes jobs later

Because the test is current use, a loan’s status can change after the day you drew it. The Folio notes that taxpayers may restructure borrowings and asset ownership to meet the direct use test; it gives an example, but whether a particular restructuring works for you is accountant territory, not something to improvise.

One related point for anyone planning to sell: the Folio says the disappearing source rules in section 20.1, which can keep interest deductible after an income source is gone, do not apply to real or immovable property. If the rental is sold and the loan stays outstanding, plan the tax side before closing, not after.

Other Line 8710 rules that ride along with borrowing

• If you claim the interest on T776, do not also claim it as a carrying charge on Form 5000-D1.
• A penalty paid to break a mortgage early, or a fee paid to reduce the rate, is not deducted in full in the year paid; T4036 has you prorate it over the rest of the original term.
• Fees to get a mortgage or loan to buy or improve the rental (applications, appraisals, mortgage brokerage and legal fees, among others) are deducted over five years, 20% a year, regardless of the loan term.
• Interest during construction or renovation follows the construction soft costs rules, which are a separate topic.

If you are about to borrow for a rental

Record-keeping steps, sorted by when they happen. They do not replace advice on your own return.