$15k Bonus on $120k: What Do You Actually Keep?
A common misconception is that bonuses are "taxed higher" than regular income. In reality, bonuses are taxed at your marginal rate — but your employer withholds tax as if you earned that bonus amount every pay period, which often means over-withholding that you get back at tax time. Your $15k bonus stays within the 30% bracket, so every dollar of the bonus is taxed at that marginal rate.
At a $120k base salary (30% bracket), a $15k bonus brings your total to $135k. The comparison below shows your take-home with and without the bonus, the actual marginal tax on the bonus amount, and how much of it you keep after tax and super. This helps you understand the real after-tax value of performance pay, commissions, or one-off payments.
Decision read
This is a material lift in take-home pay.
The alternate setup changes yearly cash enough that it should be treated as a real decision, not a rounding difference.
Baseline
Base salary
Alternate
With bonus
Result
$90,812.00Base salary
Annual gross$120,000.00
Income tax + levies$29,188.00
HELP repayment$0.00
Take-home pay$90,812.00
Monthly cash flow: $7,567.67
Effective rate: 24.3%
This scenario is using the cleaner baseline settings with no HELP debt, no bonus, and no salary sacrifice.
Result
$101,012.00With bonus
Annual gross$135,000.00
Income tax + levies$33,988.00
HELP repayment$0.00
Take-home pay$101,012.00
Monthly cash flow: $8,417.67
Effective rate: 25.2%
Bonus withholding is roughly $6,495.83, while the likely annual tax effect is $4,800.00.
Why the result moves
Compare the cash outcome, then inspect the structural reason
With bonus changes annual take-home by +$10,200.00 compared with Base salary.
With bonus changes tax and levy outflow by +$4,800.00.
The bonus scenario highlights the gap between what is withheld now and the actual annual tax effect after lodgment.
Frequently asked questions
How much tax will I pay on a $15k bonus with a $120k salary?
Your bonus is taxed at your marginal rate, not a flat "bonus tax rate." Your $15k bonus stays within the 30% bracket, so every dollar of the bonus is taxed at that marginal rate. Your employer may withhold more than the actual tax due because PAYG withholding on lump sums assumes you receive that amount each pay period. Any over-withholding is refunded when you lodge your tax return.
Why does my employer withhold so much tax on bonuses?
Employers use ATO withholding schedules that treat lump-sum payments (like bonuses) as if you receive that amount every pay cycle. A $15k bonus paid in one fortnight is withheld as if you earn $15k every fortnight — dramatically inflating the withholding rate. The ATO reconciles this at tax time, and any excess withholding becomes part of your tax refund.
Should I salary sacrifice my bonus into super?
It can be tax-effective. At $120k you're in the 30% bracket, and super contributions are taxed at just 15% inside the fund. Sacrificing some or all of the $15k bonus into super saves up to 15 cents per dollar in tax — but remember the $30,000 annual concessional cap includes employer contributions. Check your remaining cap space before committing.