Should I pay down my mortgage and borrow back the money to invest?

This question was raised to me in response to my first article on why pre-paying your mortgage is not a good idea. It is also known as ” The Smith Manoeuvre”. The key idea behind this strategy is to deduct the interest paid on an investment loan from your income.

What are the steps for this strategy?

Assuming you have $10,000 saved up at the end of the year you would do the following:

1) You put the $10,000 into your mortgage to save on the mortgage interest
2) You then borrow the same $10,000 to invest
3) You invest the $10,000 into a diversified portfolio
4) You deduct the interest paid on your investment loan from your income

Since the investment return is the same as investing the $10,000 directly instead of paying off the mortgage first the only difference is in the borrowing rates and tax treatment. The idea is that the interest deduction will more than compensate you for the higher borrowing rate you will have to pay on an investment loan vs. your mortgage.

Why makes it difficult to determine whether this works? 

What makes this particular strategy difficult to assess is the fact that it’s profitability relies on an individuals marginal tax rate after all other deductions have been counted. In non-accountant speak it means it depends on your personal income and spending situation.

Gettin’ down and dirty with the math

I know this is everyone’s favorite part and believe me I’m excited! Nothing like poring over tax brackets and figures to make me jump around in joy. Yeah I’m weird like that.

Apples to apples

We are going to compare a variable rate mortgage versus a HELOC loan.


This is because the cheapest investment loan you are likely to get is a HELOC (home equity) loan. It also takes off the table any perceived benefit of not pledging your home as collateral since both loans are backed by the house. Since all HELOC loans are variable rate loans they must be compared against a variable rate mortgage.

It’s easier to compare a variable rate mortgage because comparing a fixed rate mortgage versus a variable rate HELOC would require the stripping out the rate benefit you get due to taking on the interest rate risk (just like you do when you get a variable rate mortgage versus a fixed mortgage). It’s easier to just compare apples to apples. Picking a fixed rate mortgage versus a fixed rate loan would not change the conclusion but I do invite you to do the math yourself and perhaps post your results in the comment section.

After-Tax Interest Rates

The next step is to make the interest rate on the mortgage comparable to the interest rate on the loan through reducing the investment loan rate by the tax benefit.

This is actually very easy to do as all you need to do is multiply the HELOC rate by (1 – your marginal tax rate). Here is a table based on a 3.35% HELOC rate which is the best rate available on RateHub.

Gross income up to Tax Rate HELOC 3.35% after tax rate
$40,922 20.05% 2.68%
$44,701 24.15% 2.54%
$72,064 31.15% 2.31%
$81,847 32.98% 2.25%
$84,902 35.39% 2.16%
$89,401 39.41% 2.03%
$138,586 43.41% 1.90%
$150,000 46.41% 1.80%
$220,000 47.97% 1.74%
Above $220,000 49.53% 1.69%

Benefit versus a Mortgage

Once we have the table above it’s really easy to compare whether we could save any money by pre-paying our mortgage and borrowing to invest versus just investing the $10,000. Since the HELOC rate is already tax-benefit-adjusted we only need to compare it against the best variable rate mortgage on RateHub which today stands at 1.99%.

Therefore the benefits of the borrow-to-invest strategy per $10,000 for various individual income levels are as follows:

Gross income up to Tax Rate HELOC 3.35% after tax rate Savings vs. Variable Mortgage ( 1.99% – adjusted HELOC rate) Annual benefit per $10,000
$40,922 20.05% 2.68% -0.69% -$68.83
$44,701 24.15% 2.54% -0.55% -$55.10
$72,064 31.15% 2.31% -0.32% -$31.65
$81,847 32.98% 2.25% -0.26% -$25.52
$84,902 35.39% 2.16% -0.17% -$17.44
$89,401 39.41% 2.03% -0.04% -$3.98
$138,586 43.41% 1.90% 0.09% $9.42
$150,000 46.41% 1.80% 0.19% $19.47
$220,000 47.97% 1.74% 0.25% $24.70
Above $220,000 49.53% 1.69% 0.30% $29.93

Does this mean there is a benefit to the strategy?

It would seem from the numbers above that there is a minor benefit if you make 90K+ in gross income (the first tax bracket level where the benefit from the strategy is larger than 0) and the benefit increases a little bit as you get into higher income brackets.

However, we need to not only consider the gross income but also other deductions available to reduce this income.


Because the interest rate deduction does not apply to any loans where money was contributed to either an RRSP or a TFSA.

The tax benefits of contributing to your RRSP or TFSA will far outweigh the very minor tax benefits derived from deducting the interest. (Note: while the TFSA contribution is not tax deductible the returns are completely tax free. In the long run this tax free return benefit will be far bigger than the interest deduction.)

Adjusting the chart to account for RRSP contributions having been made

In order to determine whether it still makes sense to follow the borrow-and-invest strategy there are some adjustments that need to be made. You will need to add the RRSP contribution room available to you at each income level to the income ranges in the chart above above.

Alternatively, and maybe more intuitively, you can also subtract the RRSP contribution room from your income and compare against the chart above.

These two calculations are equivalent but I’ll do the first one to give you one easy final chart that will show you whether the borrow-to-invest strategy could work for you.

The calculation in each tax bracket is as based on 18% of your income being contributed to an RRSP up to the maximum of $24,930 allowed by the CRA.

Gross income up to Tax Rate Max RRSP contribution Gross income up to (adjusted)
$40,922 20.05% $7,365.96 $48,288
$44,701 24.15% $8,046.18 $52,747
$72,064 31.15% $12,971.52 $85,036
$81,847 32.98% $14,732.46 $96,579
$84,902 35.39% $15,282.36 $100,184
$89,401 39.41% $16,092.18 $105,493
$138,586 43.41% $24,945.48 $163,531
$150,000 46.41% $24,930.00 $174,930
$220,000 47.97% $24,930.00 $244,930
Above $220,000 49.53% $24,930.00 Above $243,087

Once we have the adjusted tax brackets we just map them back to our previous benefit table to arrive at the benefits for each RRSP contribution adjusted tax bracket.

Gross income up to (adjusted) Tax Rate HELOC 3.35% after tax rate Savings vs. Variable Mortgage (1.99%) Annual benefit per $10,000
$48,288 20.05% 2.68% -0.69% -$68.83
$52,747 24.15% 2.54% -0.55% -$55.10
$85,036 31.15% 2.31% -0.32% -$31.65
$96,579 32.98% 2.25% -0.26% -$25.52
$100,184 35.39% 2.16% -0.17% -$17.44
$105,493 39.41% 2.03% -0.04% -$3.98
$163,531 43.41% 1.90% 0.09% $9.42
$174,930 46.41% 1.80% 0.19% $19.47
$244,930 47.97% 1.74% 0.25% $24.70
Above $243,087 49.53% 1.69% 0.30% $29.93

The adjustment for RRSP contributions increases the required individual personal income to approx. $106,000 (the first adjusted tax bracket where the benefit from the strategy is larger than 0). This means that the minimum gross income level where a salaried employee should even consider this option is $106,000.

The TFSA factor

Let’s say you are lucky enough to earn $106,000 in annual income, have enough savings to contribute the full allowable $19,080 to your RRSP, and still have money left over that you need to put to work. In that case the first place you should look to put that money to work is in your TFSA. The TFSA allows for $10,000 in annual contributions but the RRSP contribution will return a nice big chunk of your taxes to you that you can use for that purpose. In the case of a $106,000 income contributing $19,080 will yield approx. $8,000 in tax return leaving you only $2,000 short of the maximum. If you contribute the full $8,000 tax return + $2,000 extra in after-tax money to your TFSA and still have money left over you might want to consider pursuing the HELOC borrow back and invest strategy.

What if you are stuck in a high fixed rate mortgage? 

This is probably the only case in which it would actually be worth the effort to go out of your way and follow this strategy. However, lets understand why that is. It is not due to the interest rate tax deduction. The reason it works is because you are in fact re-mortgaging a portion of your house at a lower variable interest rate.

If you take $10,000 out of a 3% fixed rate mortgage by paying it down, and then borrow back at a HELOC 3.35% after-tax rate of less than 3% (again depends on your marginal tax rate, see chart above) you will see a benefit. However, please keep in mind that majority of the benefit is due to the refinance of a fixed rate to a variable rate. The moment you are able to refinance your entire mortgage at a lower rate you should do that because the savings from doing that will be far larger than the benefits from the HELOC borrow back and invest strategy.

Instead of doing the HELOC borrow back strategy a more profitable approach would be to reach out to mortgage lenders and see if they would be willing to pay your penalty fee to earn your business a bit earlier.

So, should I pay down my mortgage and borrow back the money to invest?

If you earn more than $106,000, have fully contributed to your RRSP, and have maxed out your TFSA, any additional money can be used to pay down your mortgage and borrow back the money for a minor tax benefit.

Would I suggest doing it?

Let’s just say it wouldn’t be at the top of my priority list. For the vast majority of the population making less $165,000 per year in individual personal income you can save far more money expanding your energy into making sure you invest in only the lowest cost investments, limiting your trading commissions, or even bringing your lunch to work one more day a week. We all have limited time, energy and resources and the return on this strategy is so low that I wouldn’t pursue it until I’ve made sure all my other bases are covered. Given that only approx. 10% of Canadians actually exhaust their TFSA contribution limit and plan to do so in the future I think the HELOC borrow-back strategy is more of a distraction than a help for the majority of the population.

We all want to believe that there is some complex way to make extraordinary profits and if we could just figure it out and put all our energy into it we would reap amazing rewards. We chase intricate tax saving strategies and look through screens of hundreds of stocks based on obscure detailed metrics to find the perfect investment. The truth as to what is important when it comes to retirement investing, is very different, and conflicts with the way we’ve evolved to think. The important things are dead simple and really do not require much intricate knowledge (maybe some knowledge of yourself), while the complex things usually just lead to lots of time spent and very little benefit.

So save yourself some time and money and forget that expensive book or paid financial adviser pushing the next great investment or tax strategy. Instead focus on the little things that work and have always worked for generations. In return I’ll promise I’ll concentrate my posts on more useful things in the future 😉

Question, concerns, want to yell at me about how wrong I am? I invite you to click the “Leave a Reply” link below or use one of the social networks to leave a comment.

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