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£100k Salary Sacrifice & Tax Trap Calculator 2026/27

Estimate how salary sacrifice can restore your personal allowance when income exceeds £100,000.

£100k Tax Trap

2026/27 · 60% effective rate
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Salary before sacrifice£0
Salary after sacrifice£0
Personal allowance before£0
Personal allowance after£0
Income tax saving£0
NI saving£0
Total saving£0
Net cost to take-home£0

The £100k–£125,140 60% effective marginal rate

Between £100,000 and £125,140, your personal allowance tapers at £1 for every £2 of income above £100,000. The personal allowance is fully withdrawn at £125,140. This means:

Salary sacrifice reduces your gross pay, which lowers your income within (or below) this band. Each £2 of sacrifice in this zone saves you approximately £1.20 in income tax — plus NI on top — making sacrifice exceptionally valuable here.

How sacrifice restores the personal allowance

If your salary is, say, £110,000, your personal allowance is reduced by (£110,000 − £100,000) / 2 = £5,000. So instead of £12,570, your effective personal allowance is £7,570.

A sacrifice of £10,000 would bring your income to £100,000 — restoring the full personal allowance of £12,570. The income tax saving on that sacrifice is approximately £6,000 (at the effective 60% rate), plus employee NI saving of £200 (at 2% above £50,270). Total saving: ~£6,200 on a £10,000 sacrifice.

The calculator above models this precisely for your inputs.

Frequently asked questions

What is the personal allowance taper?

If your adjusted net income exceeds £100,000, the standard personal allowance (£12,570 for 2026/27) is reduced by £1 for every £2 of income above that threshold. The allowance reaches zero at £125,140. The result is an effective 60% marginal income tax rate between £100,000 and £125,140.

Does salary sacrifice count as adjusted net income?

Yes. Salary sacrifice reduces your gross/contractual salary, which in turn reduces your adjusted net income. This is different from personal pension contributions, which also reduce adjusted net income but are added back to gross pay before the calculation. Both methods are effective, but salary sacrifice also saves employee NI.

Is it always worth sacrificing to get below £100k?

Usually yes, if your employer scheme allows it and the salary is genuinely in the taper zone. The 60% effective rate makes sacrifice very efficient. However, consider mortgage affordability (lenders may use post-sacrifice salary), and check the pension annual allowance — you cannot contribute more than £60,000 in 2026/27 (or your earnings, whichever is lower). A financial adviser can help weigh the trade-offs.

What if my income is above £125,140?

Above £125,140 the personal allowance is fully withdrawn and the additional rate of 45% applies. Salary sacrifice still saves 45% income tax plus 2% NI, so the effective saving rate on sacrifice in this zone is approximately 47%. This is still highly beneficial.

Official sources

This calculator provides estimates only. It does not constitute financial, tax or legal advice. Always check current GOV.UK guidance and consult a qualified adviser before making decisions.