Most first-home purchases in New Zealand involve two incomes, two KiwiSaver balances, and one settlement date. The tools are simpler if you remember one rule: eligibility is often individual, while borrowing power is often combined.
KiwiSaver is per person
Each buyer must meet the 3-year membership rule on their own. One partner can be withdrawable while the other is still waiting. Each must usually leave $1,000 in their own account. Add the two withdrawable figures; do not assume the household balance is fully available.
If one of you has owned property before
Previous ownership does not automatically shut a couple out. A former owner can be assessed as a second-chance buyer where their financial position is comparable to someone who has never owned, and that judgement is made about the individual rather than the household. The practical consequence is that one partner may qualify on the standard route while the other needs the second-chance pathway, with different evidence and a slower turnaround. Start that assessment early — it is a common reason a two-buyer withdrawal misses its finance date.
Income is combined for borrowing
Under a 6× owner-occupier DTI lens, both gross incomes generally count before the cap. That is why a second income lifts the ceiling more than people expect — the multiplier applies to the combined total. Serviceability tests still look at household outgoings, dependants and debts.
The same logic runs in reverse for liabilities. Two people bring two sets of credit card limits, two student loans and two car loans, and all of them land on the one application. A couple with strong combined income and four unused credit cards can end up with less capacity than a single buyer earning much less. Before you apply, list every facility either of you holds, including the ones that feel dormant.
The loan is one debt, not two halves
Whatever you agree privately about who contributes what, a joint mortgage normally makes both borrowers jointly and severally liable. The lender can pursue either of you for the entire balance, not for half of it. If one person stops paying, the other has not inherited half a problem — they have inherited all of it. That asymmetry is worth understanding before you settle on a loan size, because the downside is not shared in the same proportion as the deposit.
Agree the cash story early
Who contributes what to the deposit, how gifts are treated, and what happens if you separate before settlement are uncomfortable questions that save real pain. Banks will ask for clear evidence of funds. A relationship property conversation with a lawyer is not overkill on a first purchase with uneven contributions.
Unequal deposits and contracting out
If one partner brings a much larger deposit, the default relationship property position may not match what either of you assumes. A contracting out agreement under the Property (Relationships) Act 1976 lets you record in advance what happens to those contributions if the relationship ends. Each party needs independent legal advice for the agreement to stand, which costs money and takes time — another reason to raise it before you are mid-negotiation on a property rather than during settlement week.
How you hold the title changes what happens later
New Zealand buyers generally choose between joint tenancy and tenancy in common. Under a joint tenancy the surviving owner automatically takes the whole property if one of you dies, whatever a will says. Under a tenancy in common each owner holds a defined share, which can be unequal, and that share passes under their will instead. Couples contributing very different deposits often prefer tenancy in common with shares reflecting what each put in. Your lawyer will ask which you want, and the question is much easier to answer if you have discussed it beforehand.
One offer, two timelines
Finance conditions, KiwiSaver withdrawal processing times, and building reports all sit on a shared critical path. Build slack into the finance date if either KiwiSaver provider is slow or if a second-chance previous-owner assessment is involved.
Work the numbers as a household
Run the deposit planner with both balances. Run borrowing with both incomes and honest debts. Run mortgage repayments at a rate higher than you hope to get. The goal is not a perfect forecast — it is shared clarity before you compete for a property.