How offset accounts actually work
From Aaron’s Instagram: “How offset accounts actually work”
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The short version
- An offset account links your everyday savings to your mortgage. You only pay interest on the difference.
- Your money stays available. You are not locking it away; it works against the loan while it sits there.
- Offset portions are on floating rates, so the structure is usually a mix: offset what your savings cover, fix the rest.
- Best for people who hold real cash balances: an emergency fund, business float or savings between goals.
The idea in one line
Say you owe $500,000 and you have $30,000 sitting across your accounts. With those accounts offset against the loan, you pay interest on $470,000, not $500,000. Your savings are effectively "earning" your mortgage rate, tax free, because interest you do not pay beats interest you earn and then pay tax on.
Your money is not locked away
This is the part people miss. The $30,000 is still yours, still in your accounts, still spendable tomorrow. Nothing is tied up. The bank simply nets your balances against the offset portion of the loan when it calculates daily interest.
Several NZ banks offer a version of this, and some let you link multiple accounts (including family members’ accounts in some cases), so every idle dollar in the household is quietly working against the mortgage.
Who it suits, and the catch
The offset portion sits on a floating rate, which is higher than fixed rates. So offsetting your whole mortgage rarely makes sense. The structure that works is a split: an offset portion about the size of the cash you genuinely hold, and the rest fixed at the sharper rate.
If you routinely hold real balances (an emergency fund, a tax float, savings building toward something), an offset stops that money sitting idle. If your accounts run near zero most of the month, a straightforward fixed loan with strong repayments will serve you better. Getting that mix right for your situation is a structuring conversation, and it is exactly what Aaron does.
This is general information, not personalised financial advice. For advice on your situation, talk to Aaron.
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