The questions and original answers

Congratulations on buying your first home! 🏡 Having savings left over is a great position to be in, and it's worth taking a little time to decide what to do with them rather than automatically putting everything into the mortgage.

For most first-home buyers, a sensible approach is to keep a cash safety net, set aside money for upcoming home costs, and use the remainder to reduce the mortgage if the numbers and loan conditions make sense.

The key is balancing three things: financial security, interest savings, and flexibility.

1. Start with a safety net

Owning a home changes the way you need to think about savings. If the hot-water cylinder breaks, the roof leaks, or one of you loses your income, you'll want money you can access without taking on more debt.

I'd work through these priorities first:

• Emergency fund: Aim for around 3–6 months of essential household expenses. Lean towards six months if your income is uncertain, you have dependants, or you're relying on one income.
• Home maintenance fund: Keep extra money for repairs, insurance excesses, appliances and unexpected ownership costs.
• Known upcoming expenses: Set aside anything needed for rates, insurance, moving costs, furniture or renovations you've already committed to.

Keep this money somewhere accessible, such as a suitable savings account or an eligible mortgage offset account. Don't put all of it into a mortgage structure that makes withdrawals difficult or expensive.

2. Compare the real return from saving versus repaying

Paying down your mortgage is effectively a guaranteed, after-tax return equal to the mortgage interest rate you're avoiding, provided there are no extra repayment costs.

For example, suppose your mortgage rate is 6%. Paying an extra $10,000 off the loan saves roughly $600 in interest over the first year, assuming that amount stays repaid for the full year.

If you leave that $10,000 in a savings account instead, compare the interest you earn after tax with the $600 you could save on the mortgage. I want to learn about saving - Reserve Bank of New ZealandTypes of mortgages in New Zealand, and how to choose » Sorted

Here's a simple illustration:

Option for $10,000	Approximate annual benefit
Pay down mortgage at 6%	$600 interest saved
Savings account earning 4% before tax	$400 before tax
Savings account earning 4%, taxed at 30%	$280 after tax

Illustrative rates and tax rate only, not current offers or your personal tax rate. Assumes the balance and rates stay unchanged for one year and excludes fees.

In this example, repaying the mortgage is financially better by about $320 a year. But that doesn't automatically mean you should put every spare dollar into it: accessible cash has value, especially when you're new to homeownership.

3. Check whether your mortgage lets you do both

In New Zealand, the type of mortgage you have can make a big difference. Types of mortgages in New Zealand, and how to choose » SortedMortgages and home loans

Standard fixed-rate mortgage

You get predictable repayments, but extra lump-sum repayments may be limited or trigger early repayment costs. Check your lender's annual extra-repayment allowance before making a large payment.

Offset mortgage

Eligible savings accounts are linked to your loan, reducing the balance on which you pay interest. Your money remains accessible, subject to the account terms. This can be a good compromise between saving interest and keeping a safety net.

Revolving-credit mortgage

This works somewhat like a bank overdraft. Money in the account reduces the amount you owe, and you can generally draw funds back up to your approved limit. It can be useful if you're disciplined with spending, but the available credit isn't the same as cash savings: you remain in debt.

A practical option, if your lender offers it, is to keep your emergency savings in an offset account and direct only the money you won't need into additional repayments. Ask about fees, eligible accounts, withdrawal access and the interest rate on any floating or offset portion.

4. A simple way to decide what to do with your savings

I'd use this order of priorities:

1. Pay off expensive debt first. If you have credit-card balances or high-interest personal loans, these will often be a better target than your mortgage.
2. Keep enough cash to feel secure. Set your emergency fund based on your essential expenses and how stable your incomes are.
3. Allow for the realities of owning a home. If you've just moved in, you may not yet know what repairs or purchases you'll need.
4. Compare the after-tax savings return with your mortgage rate. If mortgage repayment wins, direct the remaining surplus towards the loan, subject to any fixed-rate restrictions.
5. Automate future progress. Once you've settled into your new budget, consider increasing regular repayments or saving a set amount each payday for a lump-sum repayment when your fixed term ends.

You can also use Sorted's mortgage calculator to compare repayment scenarios and its mortgage types guide to understand your options. Types of mortgages in New Zealand, and how to choose » SortedTypes of mortgages in New Zealand, and how to choose » Sorted

5. Let's work out what makes sense for you

The right balance depends on a few numbers, especially how much savings you have left and whether your mortgage is fixed or floating. If you share a few details, I can help compare the options in New Zealand dollars.

Your home-loan snapshot

Estimates are fine. Skip any detail you're unsure of.

You don't need to find the mathematically perfect answer immediately. As first-home owners, keeping enough accessible money to handle surprises while gradually reducing expensive debt is a strong starting point.