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Relief-at-source is the most common UK personal + workplace pension contribution mechanism. You contribute from your post-tax income; HMRC adds 20% basic-rate tax relief automatically (grossing up £80 to £100 in your pension). Higher-rate + additional-rate taxpayers must claim the extra 20% or 25% relief via Self Assessment. This means basic-rate workers see all their relief automatically, but higher-rate workers who don't file SA miss out on significant relief. This guide covers mechanics, providers using it, and how to claim the extra relief.
Checked against the 4 sources listed below · Last reviewed 14 June 2026
At £50,000 salary, 8% pension contribution via relief-at-source:
You contribute £3,200 from your net (post-tax) income (£4,000 grossed up)
HMRC adds £800 (20% basic-rate relief) directly to your pension
Total in pension: £4,000
Higher-rate taxpayer: claim additional £800 back via Self Assessment (£1,600 total relief)
The Self Assessment claim
For higher-rate taxpayers:
- Complete Self Assessment tax return by 31 January
- Enter pension contributions on the "Pension contributions" section
- HMRC refunds 20% additional (higher-rate slice) OR 25% (additional-rate slice)
- Refund arrives 4-6 weeks after SA processed
Many higher-rate workers who don't already file SA miss this entirely — thousands of £ per year in unclaimed relief.
Providers using relief-at-source
Almost all UK personal pension schemes:
- SIPPs (Vanguard, AJ Bell, Hargreaves Lansdown, Interactive Investor)
- Personal pensions
- NEST workplace pension
- Some workplace schemes (particularly smaller employers)
Compared to net-pay arrangement
At £50k salary, 8% contribution
Relief-at-source
Net-pay
Take-home reduction
£3,200 (before SA refund)
£2,320
After SA refund (higher-rate)
£2,320
Same
Simplicity
SA claim required for higher-rate
Auto
For higher-rate workers who file SA anyway, both are functionally equivalent. For those who don't file SA, net-pay is better (no missed relief).
Common mistakes
Not filing SA when higher-rate — leaving thousands of £ unclaimed each year
Contributing more than you can claim relief on
Forgetting to include pension contributions on SA form
Some employers overlay salary sacrifice on top of a relief-at-source scheme. This can be confusing:
- Contribution is treated as sacrifice for tax/NI (both saved)
- But the pension provider processes it as relief-at-source mechanically
- Net effect: same as pure salary sacrifice
Ask HR to clarify if unsure.
In short
Relief-at-source is fine for basic-rate workers (all relief automatic). For higher-rate taxpayers it requires Self Assessment to capture full relief. Don't leave the higher-rate slice unclaimed — worth thousands per year for £75k+ earners.
Frequently asked questions
How does relief-at-source basic-rate work?
HMRC adds 20% relief automatically to your contribution. £80 you contribute becomes £100 in your pension.
Do I need to file SA to claim higher-rate?
Yes — if you're a higher-rate or additional-rate taxpayer, the extra 20% or 25% relief must be claimed via Self Assessment.
What if I already file SA?
Include your pension contributions on the SA form — the extra relief is refunded 4-6 weeks after SA processing.
Does my SIPP use relief-at-source?
Yes — almost all UK SIPPs use relief-at-source. Same mechanic as personal pensions.
How much do I miss if I don't file SA?
20% of your gross contribution as a higher-rate taxpayer. On £4,000/year contribution, that's £800/year unclaimed.
Salary sacrifice pension — A salary sacrifice pension scheme redirects part of your gross salary into pension before tax/NI is calculated. You save both Income Tax + NI on the sacrificed amount — 28% saving for basic-rate, 42% for higher-rate.
Net pay pension scheme — Net-pay pension arrangement deducts contribution from gross salary BEFORE Income Tax (all bands automatic) but AFTER NI. Common in large-employer defined-contribution schemes. Doesn't save NI like salary sacrifice.
Salary sacrifice — Salary sacrifice is the most tax-efficient UK pension contribution
Employer pension match — How employer matching works in 2026/27: the 3% minimum on £6,240–£50,270, common match tiers, and what unclaimed match costs.
Claim higher-rate pension relief — UK higher-rate pension tax relief above basic rate must be claimed via Self Assessment (relief-at-source schemes) or is captured automatically (net-pay/salary sacrifice). This guide covers the claim process.
NEST pension explained — NEST (National Employment Savings Trust) is the UK's default workplace pension provider set up to support auto-enrolment. This guide covers what it is, how it works, fund choices, fees, and how it compares to People's Pension + Smart Pension.
Salary sacrifice — An arrangement where you give up part of your gross salary in exchange for a non-cash benefit (most commonly pension contributions), reducing your Income Tax and National Insurance.
Sources
Tax rates and thresholds come from GOV.UK, HMRC and gov.scot. Salary and other
figures come from the organisations named below.
For the calculation methodology behind every figure on this page, see our
methodology. For our review and update process, see our
editorial standards.
Last reviewed: 14 June 2026.
Next review due 14 December 2026.
Disclaimer: This page provides general information based on published HMRC and gov.scot figures. It is not personal tax or financial advice. For your specific situation, please consult a qualified accountant or contact HMRC directly.