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
The 100%-of-earnings limit and the £3,600 floor
The £60,000 Annual Allowance is not the only cap. To get tax relief, your personal contributions in a tax year cannot exceed 100% of your relevant UK earnings — broadly your salary, bonus, self-employed profits and certain other earned income. Dividends, rental income, pension income and most savings interest do not count as relevant earnings.
So someone earning £40,000 can personally contribute up to £40,000 gross and get relief, even though the Annual Allowance would technically allow more. Employer contributions are not constrained by your earnings — only your own contributions are — which is one reason director-shareholders often route pension funding through the company rather than paying personally.
There is also a floor. If you have little or no earnings, you can still pay in up to £3,600 gross a year (£2,880 net, with HMRC adding £720 of basic-rate relief at source) and receive relief. This is what lets a non-earning spouse, a child, or someone on a career break keep a pension topped up:
Why some low earners quietly lose out
The choice of scheme mechanism matters most for the lowest-paid. Under relief at source, the provider adds 20% basic-rate relief even if you earn too little to pay any income tax — so a worker earning below the £12,570 Personal Allowance still gets the 25% uplift on their net contribution.
Under a net pay arrangement, the contribution comes out of pre-tax salary. That is fine if you pay tax — but if you earn below the Personal Allowance you had no tax to relieve in the first place, so you receive nothing on top. Two people on identical pay and identical contributions can end up with different pots purely because of the scheme their employer chose. The government has legislated a top-up scheme to compensate affected net-pay savers, paid in arrears, but it relies on HMRC matching records and many do not realise they are owed it.
If you are a low earner, it is worth asking your employer (or scheme administrator) which method your workplace pension uses. If it is net pay and you earn under the Personal Allowance, you may be entitled to a top-up.
Salary sacrifice — the extra NI layer
The worked example above shows salary sacrifice beating ordinary relief, and the reason is National Insurance. With net pay or relief at source you reclaim income tax only. With salary sacrifice you give up gross salary, so you also avoid the employee NI on that slice — and your employer avoids employer NI too.
Consider a higher-rate taxpayer redirecting £100 of gross salary into their pension by sacrifice. They would have paid 40% income tax and 2% employee NI on that £100, so the real cost to take-home pay is only about £58 for £100 in the pension. A basic-rate taxpayer sacrificing £100 saves 20% tax and 8% NI, a net cost of around £72. Many employers also add some or all of their own 15% employer NI saving to the pension, boosting the contribution further — worth asking about.
The trade-offs are real and worth weighing: a lower headline gross salary can reduce the amount a mortgage lender will offer, and can affect earnings-related statutory payments such as statutory maternity pay and sick pay. Salary cannot be sacrificed below the National Minimum/Living Wage. None of this removes the benefit for most middle and higher earners, but it is why sacrifice is a decision rather than an automatic win. Our salary sacrifice decision tree walks through when it makes sense.
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