Could your car loan and mortgage plans be pulling in opposite directions?
A client of mine financed a new car six months before we talked about her home loan. That one decision sat between the amount she wanted to borrow and the amount she qualified for. Vehicle finance is one of the most common surprises I see, and it rarely gets a second thought.
Buying a car feels like a separate part of life from buying a home. But lenders see one set of numbers, and a car loan and mortgage sit in it together with everything else. Here’s how the two connect.
Why vehicle finance weighs so heavily
A car loan is usually a fixed repayment over a much shorter term than a mortgage. Five to seven years is common these days. A shorter term pushes the monthly figure up compared with the balance, and that repayment comes straight off the income a lender counts toward a new mortgage, the same as any other debt.
It’s also usually a round, sizeable figure. A small subscription barely registers, but a fixed repayment of several hundred dollars a month registers a lot more.
Which two checks does a car loan show up in?
Lenders look at borrowing through two separate checks, and a car loan shows up in both. The first is the Reserve Bank’s debt-to-income (DTI) rules, which since 1 July 2024 have limited how much high DTI lending banks can do. Most owner-occupier lending sits around six times gross income, and investor lending around seven. DTI counts the total balance owing, so the whole car loan is in the calculation, not just the repayment. These are speed limits rather than hard caps, and settings can change, so the RBNZ explainer is worth a look.
The second check is serviceability, the bank’s own monthly cash flow test, which looks at the repayment instead. Neither carries more weight than the other, and I cover how they work together in my personal loans article.
What does this look like in a servicing calculation?
As general information only, and not any lender’s criteria: the monthly repayment comes off the income available to service the home loan. Lenders then test the mortgage at a rate above the actual one, over a term of up to 30 years. That’s why each dollar of fixed monthly commitment takes a much larger amount off the borrowing figure. A repayment of a few hundred dollars a month can lower borrowing capacity by tens of thousands of dollars, though the exact effect depends on the lender, the test rate, and the rest of the household’s finances.
Lease, loan or hire purchase: does it matter?
It can. A standard car loan has fixed repayments until the balance reaches zero. Hire purchase usually passes ownership to the buyer after the final payment, while a lease often keeps the vehicle in the finance company’s name. Some agreements also end with a balloon payment, a large lump sum due at the end of the term. Lenders can treat that differently from regular repayments, so a low repayment with a big balloon can look quite different on paper than it feels month to month.
The terms, the ongoing commitment, and any ownership transfer all shape how an agreement is assessed. Finance that looks similar can be treated very differently, so a friend’s experience rarely carries over.
Why does timing catch so many people out?
This is the one that trips up the most people. A new finance agreement signed shortly before a mortgage application changes what a lender sees: a new repayment, a balance at its highest, and a commitment with years left to run. Most people never connect the two decisions. In their minds, the car and the home sit months or years apart, but in a lender’s assessment they sit side by side. For anyone weighing up a car loan and mortgage in the same year, timing genuinely matters.
What changes when a home is on the horizon?
Even if buying a home is a year or two away, vehicle finance and the home loan timeline are linked. That doesn’t mean a car can never be financed. It means the two decisions affect each other, and seeing a car loan and mortgage side by side with the full financial position often makes the picture clearer.
This article is part of my What’s Really Holding You Back? series on debt and mortgage approval. If you missed the earlier articles, the series introduction, good debt vs bad debt, personal loans and mortgage applications and is your owner-occupier home an asset? are the best places to start. Reading the whole series in order gives the full picture of how lenders weigh debt.
This article is general information only and doesn’t take into account your personal financial situation, goals, or needs. It shouldn’t be treated as financial advice. For guidance specific to your circumstances, talk to a licensed financial adviser.
Want to know what this actually means for you?
This is general education, but your situation isn’t general. Want to go through your own car loan and what it means for your home buying timeline? I’m happy to have that conversation. As a mortgage adviser operating under Guardian Smith’s FAP (FSP1002543, individual registration FSP1012174), I can walk you through it properly. No obligation.
Call 0226584350 or email chris@guardiansmith.co.nz to book a time.
Chris Thompson
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