What happens if interest rates rise after I get my pre-approval?

Interest rates move, and it is natural to worry about what a rise does to a pre-approval you are relying on. The reassuring part is that lenders already build in a cushion for exactly this. The key to understanding it is a rule called the serviceability buffer.

The serviceability buffer, explained

When a lender assesses how much you can borrow, it does not test you only at the actual interest rate. It tests you at a higher rate, to check you could still manage if rates went up. APRA, the banking regulator, requires lenders to assess you at a rate at least 3 percentage points above the loan product rate. That margin is the serviceability buffer, and it has been set at 3 percentage points since 2021.

In plain terms, you are pre-approved on the basis that you could handle repayments well above today rate, not just at today rate.

Why the buffer is actually on your side

It can feel like the buffer just reduces how much you can borrow, and it does have that effect. But it is genuinely protective. Because you were assessed with that cushion, a moderate rise in rates after your pre-approval should not, on its own, make your repayments unmanageable. The whole point of the buffer is to leave you with room to absorb increases, which is a large part of why default rates in Australia stay low even when rates climb.

What a rate rise does to a new or renewed pre-approval

Where rates do matter is in how much you can borrow on a fresh assessment. As rates rise, the assessment rate, which already includes the buffer, rises too, and borrowing capacity across the market tends to fall. So if your pre-approval lapses and you renew it after rates have gone up, the renewed amount may come back lower than the original. This is why it is important to base your budget on a current figure, not one from months ago.

Your pre-approval amount versus the rate you pay

It helps to separate two things. Your pre-approval is about how much a lender may lend you. The actual interest rate you end up paying is generally set later, around formal approval and settlement, and can move with the market in between. So a rate change can affect both the amount you are assessed for and the rate you will pay, but they are not the same number and they are set at different times.

What happens between pre-approval and settlement

If rates move during the life of a current, valid pre-approval, the existing assessment will often still stand for that period, because it already accounted for a buffer. The greater effect comes at renewal, when a fresh assessment uses current conditions. Either way, keeping your broker informed means you are working from an accurate, up to date picture rather than a stale one.

What you can do

You cannot control interest rates, but you can give yourself room and avoid being caught short.

• Avoid borrowing to your absolute maximum, so you keep a buffer of your own on top of the lender one.
• Talk to your broker about fixed and variable options, and what each means if rates move.
• Keep your job, income and debts stable, so your borrowing power does not fall for other reasons at the same time.
• Renew your pre-approval before it lapses if you are still searching, so you always know your current position.
• Base your offers on your current assessed amount, not an older, higher one.

The bigger picture

The serviceability buffer can feel frustrating when it limits how much you can borrow, but it exists to keep borrowers safe when conditions change. APRA has kept it at 3 percentage points specifically so that recent borrowers can meet their repayments even as costs rise. Seen that way, the buffer is less an obstacle and more the reason a rate rise after pre-approval is usually something to manage calmly rather than panic about.