Pension withdrawal tax, explained
Why a big withdrawal can be taxed at a higher rate than you'd expect.
Withdrawing a large lump sum from a pension in one tax year is one of the easiest ways to accidentally push yourself into a higher tax bracket — not because the rules are unfair, but because of how the withdrawal is added to your other income.
It stacks on top of your other income
A taxable pension withdrawal isn't taxed in isolation. It's added on top of any other income you have for that tax year — salary, other pension income, self-employment profit — and taxed at whatever your marginal rate becomes once the withdrawal is included. If your other income already uses up your basic-rate band, the withdrawal can be taxed at 40% or even 45%, even if a smaller withdrawal in a lower-income year would have been taxed at 20%.
The 25% tax-free lump sum is separate
Most pensions let you take up to 25% of the pot tax-free (subject to lifetime limits). This portion sits outside the calculation entirely — it's only the remaining 75%, if and when you draw it as taxable income, that gets added to your other income and taxed at your marginal rate.
Watch the personal allowance taper
If a withdrawal pushes your total income for the year above £100,000, your personal allowance starts tapering away — £1 lost for every £2 of income above that threshold — creating an effective marginal rate higher than the headline 40% band in that income range.
Timing matters more than most people realise
Because the tax depends on your total income in the tax year the withdrawal falls in, spreading a large withdrawal across two tax years — rather than taking it all at once — can sometimes keep more of it in lower tax bands. This is exactly the kind of decision worth running past a financial adviser before acting on.
Worked example: with £30,000 of other income and a £40,000 taxable withdrawal in the same tax year, a meaningful slice of that withdrawal is taxed at 40%, not 20% — purely because of where it lands once stacked on top of the £30,000.