Child Benefit Tax Calculator — High Income Child Benefit Charge 2026/27

Between £60,000 and £80,000 of adjusted net income, every extra pound of income tips a little more of your Child Benefit back to HMRC. This calculator builds your adjusted net income up from salary, rental profit, dividends and other income, applies the exact statutory taper — rounded down to a whole percentage point, the way HMRC actually calculates it — and shows the charge, what you keep, the effective marginal rate across the band, and how much pension contribution would take you back under £60,000.

What counts as adjusted net income

Adjusted net income is your total taxable income before the personal allowance, minus the grossed-up amount of any personal pension contributions paid into a relief-at-source scheme and any Gift Aid donations. “Grossed-up” means what you actually paid, times 1.25 — because your pension provider or the charity already claimed 20% basic-rate relief on top of what left your bank account, HMRC counts the full, pre-relief amount as coming out of your income. Pension contributions taken from your pay before tax (a workplace “net pay” scheme, or salary sacrifice) need no such adjustment here — they never appear in your salary figure in the first place, so entering them again would double-count the relief.

The Section 24 catch most calculators miss

If you are a landlord, the rental profit that feeds into adjusted net income is not your after-mortgage cash profit. Since April 2020, Section 24 (ITTOIA 2005 s.272A) stops landlords deducting mortgage interest and other finance costs when arriving at property profit at all; instead, HMRC’s own Property Income Manual (PIM2058) sets out a calculation where finance costs get a “nil deduction” against rental income, and relief is given afterwards, at Step 6 of the income tax calculation, as a flat 20% credit. That means the profit figure entering your total — and therefore adjusted net income — is the higher, pre-interest figure. A landlord who feels like they are only clearing a modest cash profit after the mortgage can still be pushed over £60,000 of adjusted net income by a much bigger, pre-interest number.

How the charge itself is worked out

The charge is £60,000–£80,000: below £60,000 there is no charge at all; at £80,000 and above, the charge equals the whole year’s Child Benefit. In between, the statutory formula in section 681C of the Income Tax (Earnings and Pensions) Act 2003 (as amended by the Finance (No. 2) Act 2024 for tax years from 2024/25) is: (adjusted net income − £60,000) ÷ £200 × 100%, capped at 100% — and the result is rounded DOWN to a whole percentage point, not rounded to the nearest one and not left as a decimal. Someone £150 into the band pays back 0% of their Child Benefit, not part of 1%.

Getting back under £60,000

Because pension contributions and Gift Aid reduce adjusted net income pound for pound (after grossing up), topping up a pension is the most direct lever a taxpayer controls. Paid via salary sacrifice or a net-pay workplace scheme, £1 of extra contribution reduces adjusted net income by exactly £1. Paid into a relief-at-source personal pension or SIPP, you only need to pay 80p net for every £1 you want off your adjusted net income, because the provider’s 20% top-up does the rest of the grossing-up for you.

Opting out without giving anything up

You do not have to stop claiming Child Benefit to stop the charge — you can keep the claim and simply switch the payments off. gov.uk is explicit about what that keeps: “you would not have to pay the tax charge and you would still get National Insurance credits, which count towards your state pension.” That NI-credits point matters most for whichever partner is not earning enough to build their own National Insurance record — often the parent at home with a young child — so the claim is usually worth keeping even when the payments themselves are switched off.

Where this fits with the rest of your tax

Adjusted net income pulls together the same income sources the rest of this site calculates separately. Work the rental side through the rental income tax calculator and the Section 24 mechanics through the Section 24 guide; a salary alone through the take-home pay calculator; self-employment profit through the self-employed tax calculator; and dividends through the dividend tax calculator.

Child Benefit rates: gov.uk, “Child Benefit rates”, read 13 September 2026. Threshold, taper and the round-down rule: gov.uk, “Child Benefit tax charge”, and Income Tax (Earnings and Pensions) Act 2003 s.681C as amended by the Finance (No. 2) Act 2024 ss.5(1)–(3) (in force from 6 April 2024), legislation.gov.uk, read 13 September 2026. Adjusted net income and the pension/Gift Aid grossing-up: gov.uk, “Personal Allowances: adjusted net income”. Section 24 / property-profit point: HMRC Property Income Manual PIM2058 and gov.uk’s finance-cost-restriction worked case studies. Opting out and National Insurance credits: gov.uk, “Child Benefit tax charge” (Stop or restart your Child Benefit). General information, not advice — particularly around pension contributions, where annual allowance and carry-forward rules can also apply.