More from Opes Partners:

• Interest rate predictions - Where are interest rates heading? (Article)
• Which interest rate should I choose? (Article)
• What are the latest interest rate changes from the main banks? (Article)

#1 Should I choose a fixed or floating interest rate?

When you choose a mortgage rate, you usually have two options: fixed or floating.

A fixed rate means your interest rate stays the same for a set period. So, you know what your repayments will be.

A floating rate can move up or down. It also gives you more flexibility. You can usually make extra repayments, restructure your loan, or lock in a new rate without paying break fees.

But floating rates are often more expensive. 

Now, sometimes that’s worth it. If rates are going down, you might stay floating because you think you’ll be able to refix sooner at a lower rate.

But as of June 2026, rates are moving up, especially longer-term fixed rates. So, for many borrowers, it makes more sense to fix the bulk of the mortgage and lock in some certainty.

Most financial advisers will suggest a mix of the two.

You might still leave a small part floating, especially if you want to make extra repayments. Many borrowers do this through an offset or revolving credit facility.

That way, most of your mortgage is fixed and predictable. But you still have some flexibility.

#2 How long should I fix my mortgage?

How long you fix for depends on where you think interest rates are heading.

Typically, borrowers can fix their interest rates for 6 months and up to 5 years.

Often, the longer you fix your interest rate for, the higher the interest rate you pay. Effectively, you pay for certainty. 

Generally, borrowers choose a higher long-term rate if they think interest rates are likely to rise in the future. That way, you can lock in today's rate before rates move higher.

Though there are other reasons to lock your interest rate in for longer, too, such as if you need that certainty.

If rates do rise, borrowers who fixed for longer may come out ahead. But if rates fall (or stay the same), they could end up paying more than someone who fixed for a shorter term.

There isn't one "best" fixed term. It comes down to whether you value a lower repayment today or more certainty over the next few years.

The Opes Interest Rate Comparison Calculator can help you compare different fixed terms and see how much each option could cost you. 

#3 Which bank has the lowest mortgage rates?

The bank with the lowest interest rate changes all the time. 

One bank might have the cheapest 1-year rate. Another might have the cheapest 3-year rate. Another might offer better cashback or be more flexible with lending criteria.

That’s why choosing a bank isn’t just about picking the lowest number on a rate table.

You also need to think about:

• Can I get approved with this bank?
• Will they give me the structure I need?
• Can they give me the money in the time I need it?
• Are there fees, cashback conditions, or break costs to consider?

This is where a mortgage adviser can help. They can compare banks, negotiate, and work out which lender suits your situation.

#4 What rate will the bank negotiate?

Borrowers often ask whether banks still negotiate their interest rates. Banks are often less flexible than they used to be, and many now stick close to their advertised rates.

If another main bank offers a lower rate, your bank may match it or get close to it, especially if it wants to keep your business.

Here are the rates that Opes Mortgages is negotiating compared to the advertised rates in June 2026:

Typically, these negotiated rates are offered to most borrowers (who are eligible for the special rates). 

But, mortgage advisers and individual borrowers often can't get a substantially lower rate than what’s shown in your bank app.

#5 What’s the difference between special and standard interest rates?

The rate you see advertised by a bank isn’t always the rate you’ll get. Some will pay more; others will pay less. 

Most banks advertise “special” rates. These usually apply to borrowers who have at least 20% equity in their property.

If you have less than that, you may be offered the bank’s standard rate instead. This is a higher interest rate that borrowers pay if they have a lower deposit loan, for instance, if you buy a property with a 10% deposit.

For example, you may pay a higher rate if:

This is why it’s important to compare the rate you’ll actually get, not just the lowest rate on the bank’s website.

#6 Should I use a bank or a non-bank lender?

Not all home buyers and property investors borrow from a bank. There are also non-bank lenders. 

What’s the difference? Banks usually have lower interest rates and fees. But they also have stricter rules about who they’ll lend to.

If you don’t fit inside those rules, a non-bank lender can be useful. This could apply if you’re self-employed, have complicated income, have credit issues, or own a larger property portfolio.

The trade-off is cost. Non-bank lenders often charge higher interest rates and fees.

That doesn’t make them bad. For some borrowers, a non-bank lender is the difference between getting approved and not.

Which interest rate should I take? 

There is a lot to think about when it comes to choosing your interest rate. 

Your choice will significantly impact your mortgage repayment. 

But, as this article has shown, it’s not always a straightforward decision.

The lowest rate is not always the rate that fits your situation. The real question is which structure gives you the right balance between certainty, flexibility, and cost. 

That's why borrowers should talk to a mortgage adviser to help choose the right interest rate for them.

Not sure where to start? Use our Opes Interest Rate Comparison Calculator to see which rate might work for you.