Keep

Thresholds, tapers, and the places where earning more leaves you with less.

7 sourced figuresnext checked 1 March 2027Writing held

British tax is not a smooth curve. It has edges — points where one extra pound of income costs you far more than a pound, and cliffs where crossing a round number by £1 removes something entirely. The £100,000 line is the sharpest of them, and it is not the only one. Knowing where the edges sit is worth more than most investment decisions.

What this is not

We describe how the rules work and what the figures are. We do not tell you what to do about your own position — that needs an accountant or a regulated adviser who can see all of it.

The figures underneath

What this subject rests on

Income tax rates and bands in England, Wales and Northern Ireland.

Nil to £12,570, 20% to £50,270, 40% to £125,140, then 45%

GOV.UK, Income Tax rates and Personal Allowances · 2026 to 2027 tax year · checked again by 2027-03-01

Scotland sets its own bands and rates.

How the personal allowance is withdrawn above £100,000.

£12,570, reduced by £1 for every £2 of adjusted net income above £100,000, and nil at £125,140

GOV.UK, Income Tax rates and Personal Allowances · 2026 to 2027 tax year · checked again by 2027-03-01

Produces an effective 60% marginal rate on income between £100,000 and £125,140 in England, Wales and Northern Ireland. Scottish rates differ.

What adjusted net income is, and what reduces it.

Total taxable income before personal allowances, less certain reliefs including pension contributions and Gift Aid

GOV.UK, High Income Child Benefit Charge · 2026 to 2027 tax year · checked again by 2027-03-01

Includes foreign income. It is not the same as gross salary or taxable pay.

The income at which Child Benefit starts to be clawed back.

1% of Child Benefit for every £200 of adjusted net income over £60,000, and all of it at £80,000

GOV.UK, High Income Child Benefit Charge · From the 2024 to 2025 tax year · checked again by 2027-03-01

Free childcare for working parents in England, and the income at which it is lost.

30 hours a week for 38 weeks, ages 9 months to 4 years — lost if either parent's adjusted net income is over £100,000

GOV.UK, Free Childcare for Working Parents · 2026 to 2027 tax year · checked again by 2027-03-01

England only. Scotland, Wales and Northern Ireland run different schemes with different rules.

The Tax-Free Childcare top-up, and the income at which it is lost.

£2 for every £8 paid in, up to £2,000 per child a year (£4,000 if disabled), to age 11 — lost if either parent's adjusted net income is over £100,000

GOV.UK, Tax-Free Childcare · 2026 to 2027 tax year · checked again by 2027-03-01

Cannot be held at the same time as Universal Credit or childcare vouchers. Runs UK-wide, unlike the free hours.

Annual income thresholds and deduction rates for student loan repayment.

Plan 1 £26,900, Plan 2 £29,385, Plan 4 £33,795, Plan 5 £25,000 — each at 9%; Postgraduate Loan £21,000 at 6%

GOV.UK, rates and thresholds for employers · 2026 to 2027 tax year · checked again by 2027-03-01

Written so far

Writing held

The 7 figures above are registered, sourced and dated, and this subject’s boundary is set. The writing follows — and nothing ships without a named reviewer, so we publish fewer than two dozen pieces a year on purpose.

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