How to Make Your Mortgage Tax-deductible (Part One)

Last Updated on November 10th, 2017

by David Larock

Canadian mortgage interest can be tax deductible. Surprised? Most people I talk to about converting their mortgage to a tax deductible loan assume that a) it’s not legal b) it’s too risky and/or c) it’s too complicated. I am happy to report that none of these fears is warranted. What’s more, did you know that many Canadians could rearrange their financing today and make their mortgage interest tax-free almost immediately? So why don’t they? My theory is that the twin causes are simply a lack of information and good-old fashioned inertia (a powerful force that may be costing you thousands in tax refunds each year). Today’s post, the first of two on the topic, will lay out the facts and let you decide for yourself.

First of all, yes, it’s legal. Here is a report from the Canada Customs and Revenue Agency (CCRA) that outlines their interpretations of the deductibility of interest expense. In it, they say that if you borrow money “for the purpose of earning income from a business or property”, then the interest cost is tax deductible, provided that you have “a reasonable expectation of income at the time the investment is made”, be it in the form of interest, dividends, a combination of interest/dividends and capital gains, rents, royalties etc. The CCRA relies heavily on court decisions when formulating its policies, and here are two Supreme Court rulings in favour of the deductibility of mortgage interest, Singleton v. Canada, in 2001, and Lipson v. Canada, in 2009 (I have linked to the summaries for both cases). I say all this to reassure you that you are not testing new ground if you decide to pursue this strategy.

Keeping in mind the rules outlined above, let’s look at some examples of how a tax-deductible mortgage might be drawn up. In the simplest case, if you own a house with no mortgage on it, you would just apply for an investment loan using your house as collateral. The bank advances you the money, you invest the proceeds in appropriate assets (I strongly advise you partner with a top-tier financial planner when doing this) and when you file your taxes at the end of the year, you include the interest paid on your investment loan as a deductible expense. The amount of your refund is based on your income tax bracket so, if we assume that you paid $20,000 in interest and your marginal tax rate is 40%, you will receive a refund of $8,000 ($20,000 x .40 = $8,000). Of course, most people have existing mortgage loans and for this group, there are a few more steps involved.

For people with existing mortgages, the key step is converting your non-deductible mortgage debt into deductible investment debt. Again, using a simple example, let’s assume that you have a readvanceable mortgage (which allows you to borrow back the full loan amount at any time) of $300,000 and investments of $300,000. You could sell your investments, pay off the mortgage, reborrow the $300,000 back the next day, and then repurchase the same investments thirty days later (in accordance with CCRA rules). While you still have a $300,000 loan secured against your house and a $300,000 investment portfolio, your interest is now tax-deductible. Everything is the same, except for the large refund cheque you get from the government each April. If we assume that your marginal tax rate is 40%, and that your $300,000 mortgage is financed with a 5% interest rate amortized over 25 years, your first-year tax refund would be $5,882 ($14,706 x .40 = $5,882).

(In the example above, you want to make sure that selling your investments doesn’t trigger capital gains tax that you could otherwise delay. If you are not sure how to go about this, seek advice from a qualified financial planner. You may find that now is a good time to employ this strategy because with the recent weak performance of the markets, many portfolios may have more capital losses than gains. Triggering these losses could be very useful for several other reasons as well, although that analysis is beyond the scope of this mortgage-oriented article.)

In the two examples I’ve given so far, I have assumed that you either own your home outright or have a substantial investment portfolio. But fear not, for those of us with no investments and at least 20% equity in our homes, there is still hope thanks to a retired financial planner named Fraser Smith, a pioneer whom mortgagors enjoying tax-deductible interest should toast when their refund cheques arrive. In his book, called “The Smith Manoeuvre”, Fraser explains how we can convert our existing mortgage debt into deductible debt over time, without borrowing more money to do it. Basically you need a mortgage combined with a good readvanceable line of credit (check out my post for full details on how these work). The key feature of a good readvanceable is that every time you pay down your mortgage principal, your line-of-credit-limit increases by the same amount, so you can immediately borrow back the portion of each payment that goes toward principal and invest it instead. Over time, as your mortgage shrinks, your line of credit and investment equity grow by the same amount, gradually converting your loan from non-deductible mortgage debt to deductible investment debt. If you use your annual tax refunds to further reduce your mortgage, you can accelerate this process even more. (Note: To keep your conversion process totally cash neutral, each time you borrow back your paid-down principal, you should pay the interest on the line of credit first, and then invest the remainder.)

There is another significant advantage to this strategy. Most Canadians plan to pay off their mortgage first and then build an investment portfolio. But it takes a long time to pay off so much debt, and the earlier you invest, the longer you can enjoy the effects of compounding (which is the real magic in investing). In his book, Fraser Smith writes that “two-thirds of the effect comes from the benefits of owning your investments now instead of later. About one-third of the benefit is the effect of converting to tax deductible interest.” Instead of building equity in your home and paying non-deductible interest, you are building equity in your investment portfolio, paying deductible interest and investing the tax refunds. While it’s true that in the latter scenario you are not retiring your overall debt, you are transferring a portion of your home equity to diversified investments. If at some point you want to decrease your overall debt level and reverse part or all of this strategy, you can simply sell some or all of your investments and use the money to pay down your mortgage.

Today we’ve addressed the basic legal situation and explained the mechanics of how a tax-deductible mortgage can be set up. Next week I owe you my quarterly Mortgage Market Update, so the following week we’ll return to this topic. In Part Two, I will address some of the most common questions people have about making their mortgage tax-deductible, and provide some examples of borrowers who are well suited to consider this option. Stay tuned!

(Please Note: You should not make any changes that affect your tax status without obtaining tax advice from a certified financial planner, accountant, or lawyer. I can explain the concepts, point you in the right direction and provide the appropriate mortgage terms, but I am not a licensed tax practitioner.)

David Larock is an independent full-time mortgage broker and industry insider who helps Canadians from coast to coast. If you are purchasing, refinancing or renewing your mortgage, contact Dave or apply for a Mortgage Check-up to obtain the best available rates and terms.