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As a finance adviser we often asked what the difference is between Principal & Interest loans and Interest Only loans – otherwise known as P&I vs I/O loans.  There are a great deal of explanations online to explain this, however it’s quite often that we see only half an explanation at a time.  This article will introduce you to some of the reasons why you would choose an Interest Only (I/O) loan instead of Principal  & Interest.

Why would I choose an Interest Only loan instead of Principal & Interest?

There are actually several reasons why you would want to just pay the interest on your loan rather than paying it down, however different methods are more appropriate for different people and different scenarios.  Here are a few of the most common rules regarding how to manage your loan:

Cash Flow & Flexibility

Most people have heard the saying, “cash is king”.  If you have  any amount of debt, especially if it is substantial, you want to have the greatest amount of flexibility available to you.  In this situation, being locked into constant high repayments can – in rare situations – be a massive burden to you.  Imagine if something went a little bit wrong and you found yourself in a bit of a tight situation for a month or two (let’s say due to sickness or an unexpected large expense) your loan is going to really bite, especially if a reasonable proportion of your loan repayments are going towards paying off the loan as well as looking after the interest.

In this situation, if you were to have an interest only loan, you would be able to contact your bank, bring your monthly repayments back to just the interest while you are recovering and then put them back up to whatever you wanted them to once you feel that your cash flow can handle it.  It’s very easy to do, and it gives you the breathing space to manage your affairs a lot better than if you were locked into more restrictive credit contracts.

Interest Only Loan Tax Reason #1

You have multiple reasons for wanting an Interest Only loan when it comes to tax.  The first is again down to flexibility and is founded in the very foundation of tax law.  The ATO is more interested in what you do with the money that you claim as deductible, than where that money is from.  So if you have an investment property, the fact that the money was used to buy that property is more important than the fact that you may have used your home as security to buy it.  If you only have your home and no other borrowings, this will come into play if you decide to rent your property out in the future.

If you have an investment loan that is on a  Principal & Interest repayments, your debt is obviously going down.  The great thing about this is that if you need to get your hands on some money, you’ve been building up a buffer by paying down you debt.  The downside is that if you use any of that buffer to buy something that is not income generating (such as a car, holiday or renovation on your own home) then the interest that you have to pay on the money that pulled out is no longer tax deductible.  Why is that?  You’ve just borrowed money to buy something that is not income producing.

Had you been paying Interest Only on your loans, you could direct all your spare money to an offset account.  An offset account is a normal bank account that a bank may give you which is linked to your loan account, but is not part of your loan account.  Every dollar that you put in the offset account is a dollar that the bank will take off your debt when calculating how much interest you have to pay.  As an example, if you owed $600,000 and have $200,000 in an offset account, the bank is only going to charge interest on $400,000, even though the loan balance is still actually $600,000.  If you wanted to take out some of you savings and like before spend it on something that is not tax deductible (because it does not generate an income) then you’re not actually borrowing any money – you’re taking it out of your bank account.  You’ll be paying more interest since you’ll have less in your offset account, but because you didn’t actually borrow the money, the ATO will deem the nature of the debt to still be for investment and you’ll be able to claim the lot of it as a deduction.

Interest Only Loan Tax Reason #2

The other reason is a matter of efficiency and value.  If you are claiming the loan as being deductible, then you can assume that the ATO is effectively subsidising the cost of you debt.  Using some basic numbers:

$100,000 loan @ 5% = $5,000 interest

If the loan was for investment purposes, then the $5,000 interest is tax deductible.  If you’re on a marginal tax rate of 40%, when you do your tax return you’ll be entitle to get back $2,000 from the ATO.  Therefore, the net amount of interest is:

$5,000 – $2,000 (tax return) = $3,000.

As a result of this, we can work out our after tax net rate of interest:

$3,000 (net interest) on a $100,000 debt = 3% after tax rate of interest.

Using this formula with today’s interest rates, if you’re paying your bank 6.5% interest on your loan, your after tax net rate of interest is actually 3.9%.  That is pretty cheap money.  Now ask yourself this – if someone lent you money at 3.9% – would you want to pay it back, or would you use what money you had to investment and aim for a higher net return?  Depending on the level of risk you feel comfortable with, the answer might be very clear now as to what is the best thing for you to be doing.  A lot of people say you should pay Interest Only your loans because it keeps your tax deductions high.  Tax deduction is another word for expense that the Tax Act allows you to claim as an offset to income.  Keeping your expenses as high as possible does not sound like the right way forward, does it?  It’s similar to saying “I’ll chop my arm off, that way I don’t need to buy nail clippers” – well, that may be a little extreme.

You would want to pay Interest Only on your loan because – after tax – there may be more efficient things you could be doing with the money.  However, it all comes down to what your long term priorities are and what type of risks you feel comfortable taking on.

Another article – A question we’re always asked is “should I be paying interest only or principle and interest on my loans?”

When it comes to claiming an investment loan as a deduction – only the interest portion of the loan is tax deductible. The principle portion is not. Therefore, if you have an investment loan, and you decide to pay off some of the principle each repayment, you’re effectively reducing this tax deductible debt – meaning there is less tax you can claim back.

This can be a costly mistake for those who also have non-deductible debt (which most of us do). This includes a home loan on your Principle Place of Residency (PPOR), car loans, personal loans, credit cards, etc.

If you want to pay down any debt – it is this non-deductible debt that you should try and knock on the head first. It simply doesn’t make financial sense to pay down your deductible investment debt when you also have non-deductible debt.

So what’s the ideal structure?

Generally speaking, it’s ideal to have all of your investment loans set up as interest only.

With your PPOR debt, there are two choices to consider. If you are a disciplined saver and feel that your PPOR will one day be turned into an investment property, then it’s best to also set this loan up as interest only. However, it’s important that an offset account is set up against this loan so you can continue to make the equivalent principle repayments regularly into the offset account. The offset account is also a very handy place for parking any spare savings.

Why is it best to have my PPOR loan as interest only if I think it’s going to become an investment property? Because this debt will become deductible in the future – so you shouldn’t reduce it now.

Instead, you can place your money into the offset account which will reduce your PPOR interest repayments whilst the funds are sitting in the account. When this property becomes an investment property in the future, you can move the funds from your offset account on to your next PPOR. This way, you’ve increased your tax deductible debt and reduced your non tax deductible debt.

The interest only with an offset account doesn’t work very well for someone who isn’t a disciplined saver and will be tempted to simply make the minimum interest repayments.

If you’re not a disciplined saver and have no desire to convert your PPOR into an investment property at some point, then it’s best to have a principle and interest loan on your PPOR. Once you’ve paid off your PPOR loan and any other non-deductible debt, you may wish to start paying down your investment loans.

So in a nutshell, interest only for all loans with an offset account set-up against your PPOR loan can be a great overall structure – particularly if you think you might turn your PPOR into an investment property at some point. On the flipside, if you have no desire to turn your PPOR into an investment property down the track and you are not disciplined with money- then it’s best to have interest only against all investment loans and principle and interest against your PPOR.

For an honest and unbiased opinion, talk to Think and Grow Finance today on 03 8390 5855 or email