If your salary and spare cash already sit in a full offset account, changing from monthly to fortnightly repayments may do very little to the interest.
The money is already reducing the balance charged interest each day. Fortnightly payments can still help when they make you pay extra, or get cash against the loan earlier than it would otherwise arrive.
Those are two different changes. It is worth separating them before expecting a particular repayment schedule to take years off the loan.
Start with a $4.60 example
Say $2,000 of spare salary lands in your full offset 14 days before your monthly repayment. At a hypothetical 6% home-loan rate, keeping that money against the loan for those 14 days reduces interest by roughly:
If you instead paid the same $2,000 directly onto the loan on day one, the rough interest effect for those 14 days would be the same. In both cases the balance used to calculate interest is $2,000 lower.
The amount is deliberately small. Timing savings are real, but their dollar scale depends on the amount of money and the number of days. A fortnight does not create a special multiplier.
Now compare salary sitting in a separate spending account for those 14 days. If it does not reach the loan or offset until repayment day, that interest reduction does not happen. In that case, getting the cash there earlier changes something.
Moving cash out of a full offset to repay the loan
Suppose the loan balance is $500,000 and the full offset holds $20,000. The net amount charged interest is $480,000.
Move $2,000 from that offset straight onto the loan. The loan falls to $498,000 and the offset falls to $18,000. The net amount is still $480,000. At that instant, the transfer has changed where the money sits without changing the amount charged interest.
This does not mean the two arrangements are interchangeable. The loan balance has fallen, access to extra repayments depends on the loan terms, and future repayments or withdrawals can change the path. The example isolates the interest calculation at that point in time.
Half a monthly repayment every fortnight means paying more
Take a hypothetical monthly repayment of $3,000. Twelve payments total $36,000 over a year.
Pay $1,500 every fortnight and 26 payments total $39,000. That is an extra $3,000, equivalent to a thirteenth monthly repayment. There is a clear reason the loan could come down faster: more money has gone into it.
Compare that with spreading the original $36,000 across 26 payments. Each payment is about $1,384.62. Both schedules are fortnightly, but only one includes the extra annual amount.
Ask the lender how it calculates the fortnightly amount. Do not assume it simply halves the monthly figure. Check that your cash flow can sustain the total you are choosing, and that extra payments are allowed under the product.
Moneysmart's repayment guide explains the extra annual payment created by fortnightly halves and the need to check extra-repayment rules.
Compare one change at a time
In the Repayment Planner, enter your current loan amount, rate and remaining term. Start with the offset balance you normally keep, then switch fortnightly halves on and off.
The planner treats fortnightly halves as its own strategy because it adds repayments over the year. If you also enable extra repayments, you are testing more than one change. Read the combined result as a combined plan.
This is a model, not a recreation of your bank statement. It does not reproduce daily salary deposits and bill withdrawals. Use the worked example above for the timing question, and the planner for a broader estimate of the loan path.
A useful check before changing anything
- Where does your spare cash sit between payday and repayment day?
- Is the offset full and correctly linked to the loan you are modelling?
- Does the new payment amount increase what you pay over a whole year?
- What access conditions and repayment limits apply to your product?
A schedule that suits your pay cycle can be easier to manage. That is useful in itself. Just be clear about whether the benefit comes from timing, paying more, or making the routine easier to maintain.
Keep a note of the inputs if you want to revisit the comparison after your savings or rate changes. If you pay extra for the offset feature, also check the balance it needs to cover its costs.
Examples are hypothetical, not current product offers. Source guidance checked 9 September 2026.