Car finance when your partner has bad credit

If one of you has a poor credit file, you have three routes: the stronger file applies alone, you apply jointly, or someone acts as guarantor. Each puts a different amount of risk on a different person. Nobody can promise approval, so choose the route that leaves you both safe.

By the Editorial team · Updated 9 November 2026

When you share a household, a car is usually a shared need. If one of you has a clean file and the other has defaults, it is natural to ask whether the better file can simply carry the loan. Sometimes that works. Sometimes it creates a bigger problem than it solves. This page walks through your three routes, what a lender looks at, and how to keep both of you safe.

Three routes, one at a time

Route 1: the stronger file applies alone. The person with the better credit and steady income applies in their name only. The lender assesses that person. The upside is a simpler application and a rate that may suit a stronger file. The downside is that all the responsibility sits on one person, whoever uses the car.

Route 2: you apply jointly. You both sign. The lender assesses both of you, usually looking at your combined income and combined costs. If you are both on the contract, you are both party to the loan, which means the lender can look to either of you. Read the contract carefully to see whether each of you is responsible for the whole debt. That is how joint loans commonly work.

Route 3: someone acts as guarantor. A guarantor is the lender’s back-up. Consumer Protection describes it plainly: a guarantor repays the borrower’s debt if the borrower does not. A guarantor is not usually a partner who lives with you, and the lender must check the guarantor can afford to take over the repayments without substantial hardship.

What lenders look at

Whichever route you take, the lender asks the same questions of the people on the loan:

Income. Payslips, bank statements, or benefit and Working for Families statements.
Costs. Rent, power, childcare, food, other debts and credit cards.
Credit files. Each person has a separate file at each credit reporter. See how to check your credit score.
Stability. How long you have been in work and at your address.
The car. Price, age and what it is for.

Under the Credit Contracts and Consumer Finance Act, the lender must be satisfied you can make the repayments without substantial hardship. A household with two incomes can show more room, but a household with one weak file may still face a higher rate.

The risks nobody mentions at the yard

Dealers sometimes talk about a partner as if they were a tick-box. They are not. Consider these before you choose:

The strong file takes the risk. If the better credit owner applies alone and the payments are missed, it is their record that suffers.
Joint means joint. If the relationship ends, the loan does not split in half. Your agreement with your partner and your agreement with the lender are two separate things.
A guarantor can lose assets. Consumer Protection says a guarantor’s home, car or other assets could be repossessed if the borrower cannot pay.
An “all-obligations” guarantor arrangement can cover more than the car. Consumer Protection explains it can cover all the borrower’s debts with that lender, including future ones. You can ask for it to be limited, but the lender may say no.
Pressure. The lender must not force a guarantor to sign, and nobody else may either. If you feel pushed, stop.

A worked example, for illustration only

Take a couple who both work. The numbers are invented and rounded, and the repayment is not a quote. Say they want a $9,000 car on about a $75 weekly payment, with a further $20 a week for insurance.

Weekly, illustrative	Partner A alone	Both together
Take-home pay	$900	$1,900
Rent, power, food, phone, other costs	$780	$1,350
Left before the car	$120	$550
Car repayment and insurance	$95	$95
Left after the car	$25	$455

On one income, the car leaves almost nothing for a surprise. On two, there is a cushion. That cushion is what a lender sees when it looks at a joint application. It is also why the person with the weaker file should still be on the paperwork honestly, rather than hidden. Hiding someone’s income or debts from a lender is not a trick that helps you: it can lead to a loan that does not suit you.

Your steps, in order

Each of you gets your own credit reports. Compare them. Fix errors before you apply. See what is a bad credit score if you want to know where each of you sits.
Write down a joint budget. Include what happens if one income drops.
Decide who drives, who pays and who owns. Put it in writing between you.
Choose your route. Alone, joint or guarantor, based on safety first and approval odds second.
Apply once. Several applications leave several enquiries on both files.
Read the contract together. Ask who is responsible if one of you cannot pay.
Keep copies of the contract and the disclosure statement.

A checklist before you sign

Do we both understand we may each be responsible for the whole loan?
Is the repayment still affordable if one of us loses hours?
Do we have a written plan for who pays if we separate?
If we use a guarantor, have they had independent advice?
Do we know the total cost in dollars?
Has anyone promised us approval? If so, stop.

If you are already behind, or a partner is leaving

If payments are slipping, contact the lender early. Consumer Protection says that if an unexpected life event makes repayments hard, such as job loss, serious illness or a relationship breakdown, you can apply for hardship. The lender must decide within 20 working days and must pause repossession while it considers it. Details are at can my car be repossessed.

Red flags

A dealer who wants a partner to “just sign here” without a copy of the contract.
A lender that will not explain what a guarantor or joint borrower is responsible for.
Pressure to add a family member as guarantor today.
Add-ons such as insurance or a warranty added to the loan without you asking.
A lender that is not on the Financial Service Providers Register. It cannot legally give credit.

Cheaper or gentler options

A free financial mentor or MoneyTalks can help you build a joint budget.
Community Law centres give free initial legal advice, which is worth having before anyone becomes a guarantor.
Work and Income can sometimes help with essential costs. Ask about your situation.
Good Shepherd NZ and Nga Tangata Microfinance offer low-interest or no-interest loans for essentials.
A smaller car that one income can carry comfortably.

Talking it through with your partner

Money conversations are hard, especially when one person feels judged for their credit. A few ground rules help. Start with the goal, which is reliable transport for the household, not who made the past mistakes. Share both credit reports openly, so nobody is surprised later. Agree a weekly amount you can both live with, and agree what you will do if one income drops.

If the person with the weaker file is nervous about being on the contract, that is worth respecting. They may prefer to wait and rebuild, and let the other person apply alone with a written agreement between you. The safest plan is the one both of you would still be comfortable with in a year, not only on signing day.

What happens when you use our check

Our check asks four quick questions. It is not a credit application. A broker partner may then call you to talk through your options, including whether one of you applies or you apply together. Lenders do their own checks and make their own decisions. We are a referral service, you do not pay us, and we are paid by lenders only if a loan settles. See how we are paid.

Sources

Ready to see your options? Start the four-question check.

Common questions

They can, and a lender will assess their income, spending and credit file. But the loan is then theirs. If payments stop, they are the one chased, and their file takes the hit. Agree who pays, and what happens if you split up, before anyone signs.

Lenders generally look at both people, so a weak file on one side can still matter. Some lenders weigh combined income and affordability heavily. Others are more cautious. Lenders decide case by case, and nobody can promise approval.

A joint borrower is a full party to the loan. A guarantor is a back-up who repays if the borrower does not. Consumer Protection says a guarantor can be asked for fees and interest too, and that their home, car or other assets could be at risk.

The lender is not bound by your relationship. If you are both on the contract, check with the lender about who is responsible. Free legal advice from a Community Law centre can help before you sign, not afterwards.

Think hard first. Consumer Protection advises avoiding a loan that needs a guarantor if possible. If it is the only way, the guarantor should get independent advice before signing.