The income at which the Personal Allowance starts to be withdrawn has been £100,000 in all 17 tax years in this series, back to 2010/11. It has never been raised. Over the same period the band across which the allowance is withdrawn has grown from £12,950 wide to £25,140 wide, because the band's width is set by the Personal Allowance and the allowance has risen.
What the taper does
Most people can earn up to the Personal Allowance before income tax starts. Above a fixed level of income that allowance is withdrawn: for every two pounds of income above the line, one pound of allowance goes. In 2026/27 the line is £100,000 and the allowance is £12,570, so the allowance reaches nil at £125,140.
Between those two incomes each extra pound is taxed twice over: once as income, and again because it drags a further fifty pence of previously tax-free pay into tax. That is why the band is called a trap. In 2026/27, on the next £1,200 of pay inside it, £744 goes in income tax and National Insurance — a marginal rate of 62%, against 61% in 2010/11.
The income that matters is adjusted net income, not gross pay. This study assumes they are the same: employment income only, no pension contribution, no student loan and no other income. If you pay into a pension or give under gift aid, the two differ, and you cross the line at a different salary.
A threshold that has not moved
The single clearest thing in the table is a column that does not change. The withdrawal threshold is £100,000 in 2010/11 and £100,000 in 2026/27, and in every year between. It is a cash figure written into statute, not linked to prices or to earnings, so it stays where it is until a Chancellor moves it. Across 17 tax years, none has.
Every other number on the row has moved. The Personal Allowance has risen from £6,475 to £12,570. The basic rate limit, the National Insurance thresholds and the highest rate of income tax have all been changed, some of them more than once. The line at which the allowance starts to disappear has not.
That has a consequence the table makes plain: a salary that was comfortably clear of the threshold in 2010/11 can sit inside the band today without its owner having done anything except be paid more in cash terms.
How wide the band has become
Because the allowance is withdrawn at one pound for every two pounds of income, the width of the band is exactly twice the Personal Allowance. When the allowance rises, the band gets wider, and the income at which it ends moves up with it.
In 2010/11 the allowance was £6,475, so the band ran from £100,000 to £112,950: £12,950 of pay. In 2026/27 the allowance is £12,570, so the band runs from £100,000 to £125,140: £25,140. The band is 94.1% wider than it was.
From 2023/24 the top of the band and the start of the highest rate of income tax have been the same figure, £125,140. Before that year the highest rate started well above the point at which the allowance had already run out, and the two were separate boundaries.
What the band costs across its whole width
Take a person paid exactly the threshold and a person paid exactly the income at which the allowance runs out, in the same year, under rest-of-UK rates. In 2026/27 the first takes home £68,557.96 and the second £78,111.16. The second is paid £25,140 more and keeps £9,553.20 of it; £15,586.80 goes in income tax and National Insurance.
In 2010/11 the same comparison was £5,050.50 kept out of £12,950, with £7,899.50 deducted. The share taken has barely moved — 61% then, 62% now — but because the band is wider, the cash taken across it has roughly doubled.
The rate inside the band has been 62% in every year of the series but two. In 2010/11 it was 61%, because employee National Insurance above the upper earnings limit was charged at a lower rate. In 2022/23 it was 62.73%, because that rate carried the Health and Social Care Levy for the year.
What this study does not say
It counts nobody. We hold no verified figure for how many people have income inside the band, so none is given here. A number we could not show you the source for would not be worth publishing.
The figures are nominal pounds. Nothing here is converted into today's money, because a real-terms series needs a price index we are not yet in a position to show you, and a comparison across 17 years without one is a comparison of cash amounts and nothing more.
It covers the rest-of-UK rates and bands. Scottish rates begin part way through the series, so a Scottish column would be empty for the first years and would not be a like-for-like line. And it says nothing about what anyone should do: this is a description of what the rules do, and we do not give financial advice.
The figures for 2026/27 were built from rules version 2026.10, and each earlier year from its own published version, which the CSV records row by row. When a rules file changes, the page and the file change with it and the changelog says why.