Pension tax relief returns the income tax paid on money you contribute to a UK pension. Basic-rate taxpayers get 20%, higher-rate 40%, additional-rate 45%. For someone in higher rate, that means £100 in the pension costs only £60 of take-home pay. Tax relief is the most powerful incentive in the UK savings system.
The three ways tax relief is applied
| Method | How it works | NI saving? |
|---|---|---|
| Net pay | Contribution comes from gross (pre-tax) salary. Taxable income reduced by contribution amount. | No (unless via salary sacrifice) |
| Relief at source | Contribution paid from net (post-tax) pay. Provider claims basic-rate (20%) relief from HMRC and adds to pot. Higher-rate claim extra via Self Assessment. | No |
| Salary sacrifice | Gross salary reduced by agreed amount. Employer pays equivalent into pension. | Yes — saves both employee and employer NI |
Most workplace pensions use net pay. Personal pensions / SIPPs use relief at source. Salary sacrifice is the most efficient but requires employer agreement and can't go below the £6,240 lower earnings threshold.
Worked example: £100 into pension at each tax band
| Tax band | Net cost of £100 contribution | Effective relief |
|---|---|---|
| Below Personal Allowance (£12,570) | £80 (only basic-rate relief at source) | 20% |
| Basic rate (£12,571 – £50,270) | £80 | 20% |
| Higher rate (£50,271 – £125,140) | £60 | 40% |
| Additional rate (£125,141+) | £55 | 45% |
| 60% trap (£100,000 – £125,140) | £40 | 60% |
| Salary sacrifice (higher rate) | £58 | 42% (40% IT + 2% NI saved) |
| Salary sacrifice (60% trap) | £38 | 62% (40% IT + 20% PA taper effect + 2% NI) |
The 60% trap row is the killer. Each £100 sacrificed into pension from the £100,000-£125,140 band of income reclaims £62 — vs only £42 of "relief" on basic rate. Most affected higher earners structure pension sacrifice to fully cover the trap band.
How higher-rate taxpayers claim the extra relief
If your pension uses Relief at Source (most personal pensions, SIPPs) and you're a higher-rate or additional-rate taxpayer, the provider only claims 20% basic-rate relief. You have to claim the extra 20% (higher) or 25% (additional) via Self Assessment or directly to HMRC.
Worked example. Basic-rate taxpayer pays £80 net into SIPP. Provider grosses up to £100 (adds £20 relief). Pot grows by £100.
Higher-rate taxpayer pays £80 net into SIPP. Provider adds £20 (basic-rate). They file Self Assessment claiming the additional £20 of higher-rate relief. HMRC refunds £20 — either as cash, or as a reduction in their tax bill, or a tax-code adjustment.
Annual Allowance — the cap on contributions getting relief
Tax relief is unlimited in rate but capped by amount. The Annual Allowance is £60,000 in 2026/27 — the total pension contributions (employee + employer + tax relief) eligible for tax relief each year.
Higher earners face a tapered annual allowance: the £60,000 reduces by £1 for every £2 of "adjusted income" above £260,000, down to a £10,000 minimum. The pension annual allowance calculator works through the maths.
If you don't use the full Annual Allowance, unused capacity can be carried forward up to 3 tax years. The carry-forward calculator computes the available headroom.
Compare your pension contribution methods
The salary sacrifice calculator compares net pay, relief at source and salary sacrifice with your specific tax position.
Open the salary sacrifice calculator →Sources and methodology
Pension tax relief rules from gov.uk/tax-on-your-private-pension/pension-tax-relief. Annual Allowance from gov.uk/tax-on-your-private-pension/annual-allowance. Carry-forward rules from HMRC Pensions Tax Manual.
UK Tax Drag is not authorised by the Financial Conduct Authority and does not provide regulated financial advice — see the content disclaimer for the full position. The methodology page documents how every calculator is built and reviewed.
Related
- Salary sacrifice calculator — most efficient contribution method comparison
- Pension annual allowance calculator — check the £60k cap including taper
- Pension carry-forward calculator — use unused allowance from prior years
- Should I salary sacrifice? — decision framework with relief considered
- Full UK money glossary
- FAQ library
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