Does a car loan affect your home loan borrowing power?

Yes. And usually by more than the car is worth.

That is the short answer, and it surprises people every week. A car loan does not just sit beside your home loan application as a line item. It is deducted from the income a lender will let you borrow against, in full, for the whole assessment. The result is that a repayment that feels manageable on a Thursday payday can quietly take a serious bite out of what a bank will lend you for a house.

This page explains how that assessment actually works, why the timing of the car matters as much as the loan itself, and what your options are if you have already signed. It is general information, not personal advice, but it is the same explanation we give clients across the desk.

How lenders actually assess a car repayment

When a lender works out your borrowing power, the process is broadly the same everywhere, even though the settings differ bank to bank:

1. They start with your income. Base salary is counted in full. Overtime, bonuses, commissions and casual income are often only partly counted, and the treatment varies by lender.
2. They subtract living expenses. Either your declared spending or the lender's benchmark figure for a household like yours, whichever is higher.
3. They subtract your existing commitments. Every ongoing repayment you are contracted to make: personal loans, HECS, buy now pay later accounts under some policies, credit cards, and yes, the car loan. The car repayment comes off your surplus in full, every month, for the whole assessment.
4. What is left is your surplus, and the lender tests whether that surplus can support the proposed home loan at a buffered assessment rate, which sits well above the rate you would actually pay. The buffer exists so you can still afford the loan if rates rise.

Here is the part that stings. Because the home loan is measured over a long term, every dollar of monthly surplus supports many dollars of borrowing. That multiplier works in reverse too: every dollar of monthly car repayment removes many dollars of borrowing power.

As a purely illustrative example, with deliberately round numbers that are not any lender's actual figures: if each $100 of monthly surplus supports somewhere in the order of $15,000 to $20,000 of home lending under a buffered assessment, then a $700 monthly car repayment is not a $700 problem. It is potentially a six figure reduction in what you can borrow. The exact multiple moves with the assessment rate, the loan term and the lender's policy on the day, which is why we will not pin a number on it here. If you want to see the shape of the maths on your own income, our borrowing capacity calculator lets you run your numbers with and without an existing debt and watch the result move.

One more wrinkle worth knowing: credit cards are assessed on the limit, not the balance. A card you never use still drags on your capacity. A car loan is assessed on the repayment. Different mechanisms, same direction.

Why the hit is bigger than the car

Three things make car loans punch above their weight in a serviceability assessment.

The term is short, so the repayment is high. A car loan runs over something like five to seven years, against thirty for a mortgage. That compresses the balance into a chunky monthly figure, and the assessment cares about the monthly figure, not the balance.

The lender counts it for the whole assessment, even if it is nearly done. With limited exceptions that vary by lender, a car loan with eight months left is treated much the same as one with five years left. You cannot count on a lender ignoring it because the end is in sight.

Balloon payments do not make the problem go away. A balloon shrinks the monthly repayment by parking a slab of the principal at the end of the term. Some assessments still look through to the whole obligation, and either way you will owe that balloon right around the time you are trying to do other things with your money. If you are weighing up a balloon, read our plain explanation of how a chattel mortgage works, because the same balloon logic applies.

Timing: the car comes after the keys

If you are planning to buy a home in the next year or two, the order of operations matters more than almost anything else on this page.

Buy the house first. Get the keys. Then buy the car.

Once your home loan has settled, the equation resets. Your borrowing power has done its job, the mortgage is in place, and a sensible car loan afterwards is a budgeting decision rather than a threat to your application.

Do it the other way around and you walk into the lender's office with your surplus already spoken for. We have seen buyers lose more purchasing power to a new ute than the ute cost, simply because the loan landed a few months before the home application instead of a few months after.

And one hard rule for the window between loan approval and settlement: take on nothing new. No car, no card, no interest free furniture package. Lenders can re-verify your position before settlement, and new debt in that window can put the whole purchase at risk.

The tradie and business angle: structure changes the picture

If the vehicle is genuinely for work, the conversation changes. A ute or van used predominantly for business is usually financed under a chattel mortgage in the business name rather than a personal car loan in yours. The business owns the vehicle, the expense runs through the business financials, and the tax treatment follows, which we work through alongside your accountant.

For home loan purposes, the difference can matter. Some lenders assess a business vehicle commitment that already sits inside the business financials differently from a personal loan repayment that comes straight off your household surplus. This is lender by lender territory, not a rule you can bank on, and it is exactly the kind of thing a broker checks against actual policy before you sign anything. What we can say plainly: signing a personal car loan for a work vehicle right before a home application is usually the worst available version of the structure.

If you are on the tools and going out on your own, our WA tradie finance checklist covers this trap and the rest of the setup work in one place.

Already have the car loan? Your options

Plenty of people arrive at the home loan conversation with the car loan already in place. It is not fatal. The options, roughly in the order we look at them:

• Get the payout figure and do the maths both ways. Paying the loan out restores the surplus, but it also drains the deposit, and deposit size affects your loan in its own way. Sometimes clearing the loan wins, sometimes keeping the cash wins. It is arithmetic, not instinct.
• Restructure the car loan. A different term or a sharper deal on the same car can lower the monthly commitment the lender assesses.
• Pick the lender whose assessment suits you. Lenders treat the same car loan differently. Matching your position to the lender whose policy fits it is the core of what a broker does, and it is why two banks can give the same person very different answers. Our residential finance page covers how we approach that across the panel.
• If you already own a home, the loan you have is part of the same picture. A stale rate on the mortgage costs surplus too, and it is often the easiest thing to fix. Our free rate check will tell you whether yours is still competitive.

When a car loan is fine

None of this means a car loan is a mistake. A car loan is fine when:

• Your surplus comfortably covers both the car and the home loan you want, with room left over.
• You are not planning a property purchase in the next couple of years.
• The vehicle earns income and is structured properly through the business.
• You have sized the repayment against the borrowing power you actually need, not against the maximum a dealer will approve.

The problem is never the car. It is the order and the structure. Both are cheap to get right and expensive to get wrong.

Talk to us before you sign

Five minutes before you sign a car loan can protect six figures of borrowing power. Tell us what you are buying and when a home is on the radar, and we will give you a straight answer on the structure, the timing and what it does to your next application. Book a time or call 0483 292 005.

General information only. Everyone's position is different, and lender policies change. We will work through your specific numbers with you, alongside your accountant where the vehicle is for business.

Frequently asked questions