Understand bonus interest before you chase the top rate.
This page explains what bonus interest is, what one missed month costs, and why the strongest advertised rate can still be the wrong fit if the conditions, caps, or intro rules do not match your setup.
What bonus interest actually means
A bonus interest savings account combines a low base rate with a much higher bonus rate that is only paid for months in which you meet the bank's conditions. The advertised number is the two added together, so it is conditional, not automatic.
Example: an account with a 0.05% base rate and a 5.45% bonus rate advertises 5.50% p.a. On $10,000 that is about $45.83 of interest in a month you meet the conditions, but only about $0.42 of base interest in a month you do not. One missed month costs roughly $45 on that balance, and about $454 on $100,000.
The most common conditions
The usual rules are a minimum monthly deposit (often $200–$2,000), no withdrawals in the month, growing the balance by a set amount, a minimum number of card purchases on a linked transaction account, or simply holding that linked account. Some banks assess the condition one month and pay the bonus the next, so the first month of a new account can earn base rate only.
Each rule changes the real effort involved. Two products can show the same advertised rate while requiring very different behaviour to earn it, which is why our guides show the conditions next to the rate rather than the rate alone.
Why the headline rate can be misleading
A headline rate does not tell you whether there is a balance cap above which the bonus stops, whether the bonus is on the whole balance or only part of it, or what the rate falls to after an intro period. On $150,000 with a $100,000 bonus cap at 5.45% and a 0.05% base rate, the effective rate on the full balance is about 3.68% p.a., not 5.50%.
For larger balances, a slightly lower rate with a higher cap, or a split across two accounts, often produces more interest than the single account with the biggest advertised number.
How to use this when comparing accounts
Before acting, check the official bank page for the current rate, the exact monthly conditions, any balance cap, whether the bonus is limited to new customers, and whether a linked account is required.
Then run your own balance and time frame through Savings Planner. It estimates interest with the conditions met every month and shows a no-conditions alternative beside it, so you can see what the bonus is actually worth to you.
Bonus-rate savings accounts right now
As of 14 Oct 2026, the highest advertised savings rate for bonus-rate savings accounts in our dataset is 6.25% p.a. from ING Savings Booster (4-month intro, then 5.65% p.a.), which requires you to grow the balance by at least $100 by month end.
| Bank | Product | Max rate | Ongoing rate | Intro offer | Top rate applies to | Conditions |
|---|---|---|---|---|---|---|
| ING | Savings Booster | 6.25% p.a. | 5.65% p.a. | 4-month intro 6.25% p.a. | Any balance | Grow the balance by at least $100 by month end. |
| ING | Savings Maximiser | 5.75% p.a. | 5.75% p.a. | — | Up to $100,000 | Deposit at least $1,000 each month. Make at least 5 card purchases each month. Finish the month with a higher balance than you started with. |
| IMB Bank | Reward Saver Account | 5.60% p.a. | 3.45% p.a. | 4-month intro 5.60% p.a. | Up to $1,000,000 | Deposit at least $50 each month. Make no withdrawals during the month. |
| ANZ Plus | ANZ Plus Growth Saver | 5.35% p.a. | 5.35% p.a. | — | Any balance | Grow the balance by at least $100 by month end. |
| Australian Mutual Bank LTD | Momentum Saver Account | 5.35% p.a. | 5.35% p.a. | — | Up to $250,000 | Deposit at least $100 each month. Make no withdrawals during the month. |
| Bankwest | Hero Saver | 5.35% p.a. | 5.35% p.a. | — | Any balance | Make at least 1 deposit each month. Grow the balance by at least $0 by month end. |
| Great Southern Bank | Goal Saver | 5.35% p.a. | 5.35% p.a. | — | Up to $50,000 | Deposit at least $500 each month. Make at least 5 card purchases each month. |
| Suncorp | Growth Saver Account | 5.35% p.a. | 5.35% p.a. | — | Any balance | Grow the balance by at least $200 by month end. Make no more than 1 withdrawal each month. |
Frequently asked questions
What happens if I miss the conditions one month?
You earn the base rate for that month instead of the bonus rate. On a 5.50% p.a. account with a 0.05% base rate, missing one month on $100,000 costs about $454 of interest. Most banks reset the next month; a few also count the miss against an intro period.
Is a bonus rate account better than a no-conditions account?
Only if you meet the conditions every month. If the bonus rate is 5.50% p.a. and the best no-conditions rate is 5.00% p.a., the bonus is worth about $500 a year on $100,000, so one missed month (about $454) wipes out most of the advantage. Compare the two on your own balance in Savings Planner.
Does the bonus apply to my whole balance?
Usually only up to a cap, commonly between $50,000 and $250,000. Above the cap the balance earns the base rate. If your balance is above the cap, splitting across two accounts or choosing a product with a higher cap generally earns more.