Adjusted net income is one of those tax terms that never quite makes the news but quietly decides some of the most important thresholds in UK tax: the High Income Child Benefit Charge, the tapering of the personal allowance, and Tax-Free Childcare eligibility all depend on it.
The number is close to your total taxable income but not identical. Using the wrong figure is a common reason for unexpected tax bills.
How to calculate adjusted net income
- Start with total taxable income (salary, rental profit, self-employment profit, pension, savings interest, dividends).
- Add the gross value of pension contributions made through relief at source (usually personal pensions outside of salary sacrifice).
- Deduct the grossed-up amount of those same contributions — in effect taking account of the tax relief you received.
- Deduct Gift Aid donations, grossed up.
- Deduct trading losses.
The result is your adjusted net income. It is always lower or equal to your total taxable income.
Why it matters
High Income Child Benefit Charge
From April 2024, the charge starts at £60,000 of adjusted net income and phases out fully at £80,000. If your adjusted net income is £70,000, you lose half of the family's Child Benefit through the charge. Run the numbers through our Child Benefit calculator if you want to see the exact effect.
Personal allowance taper
The personal allowance reduces by £1 for every £2 of adjusted net income over £100,000 and disappears at £125,140. Because this happens on adjusted net income, pension contributions are especially powerful in this range — they can restore the allowance and give an effective marginal tax rate of around 60 per cent.
Tax-Free Childcare
You lose eligibility for Tax-Free Childcare once your adjusted net income exceeds £100,000. A large bonus can therefore cost you more than the tax on the bonus itself once childcare support is removed.
A worked example
Imagine a salary of £72,000, a bonus of £5,000, and a personal pension contribution of £4,000 net (£5,000 gross after basic-rate relief).
- Total taxable income: £77,000.
- Less grossed-up pension contribution: £5,000.
- Adjusted net income: £72,000.
The Child Benefit charge now applies to 60 per cent of the benefit rather than 85 per cent, and the family keeps more of it simply by funding a pension more deliberately.
Why this catches people out
Most workers only know their gross salary and their P60 figure. They often do not know that pension relief and Gift Aid change the measure HMRC cares about for these thresholds. That is why a short adjusted net income review — especially before December in a bonus year — can save serious money.
Pair our salary calculator with our pension calculator to map out the likely adjusted net income for the year.
The bottom line
Adjusted net income is not glamorous, but it is the threshold that actually bites. If you are near £60k, £80k, £100k, or £125k in any year, run the calculation before it decides things for you.