See how much tax relief is added to a relief-at-source pension contribution.
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What this calculator covers and how the numbers are worked out
This calculator shows how tax relief boosts what you pay into a pension, and roughly what a contribution actually costs you once relief is accounted for. It's designed for anyone contributing to a personal pension, SIPP or workplace scheme who wants to understand the gap between what leaves their bank account and what lands in their pension pot.
Most personal pensions and many workplace pensions use what's called relief at source. Under this method, you pay in 80% of the gross amount you want to end up in your pot, and your pension provider automatically claims the other 20% from HMRC and adds it. So if you want £1,000 to land in your pension, you actually only pay £800 yourself, the provider claims £200 from HMRC and tops your contribution up to the full £1,000.
Basic-rate taxpayers get their full 20% relief automatically through this mechanism, no extra steps needed. But if you're a higher-rate or additional-rate taxpayer, the 20% added at source is only part of what you're entitled to, and you have to actively claim the rest back yourself through Self Assessment, it is not added to your pension automatically.
Here's a worked example for a higher-rate taxpayer. Suppose you want £1,000 to land in your pension pot through a relief-at-source scheme. You pay in £800, and your provider claims the basic 20% relief, £200, from HMRC automatically, bringing your pot to £1,000. As a 40% taxpayer, you're entitled to 40% relief overall on that £1,000, which is £400, but only £200 of that has been applied so far. You then claim the remaining £200 back via your Self Assessment tax return, either as a refund or a reduction in your tax bill, bringing your true net cost down from £800 to £600 for £1,000 in your pension.
The same idea applies at the additional rate. An additional-rate taxpayer is entitled to 45% relief overall, so on that same £1,000 contribution they could claim back an extra £250 through Self Assessment on top of the £200 basic relief added automatically, bringing their true net cost down to £550.
Not every workplace pension works this way. Many use a net pay arrangement instead, where your contribution is taken out of your salary before tax is calculated on it, rather than being paid from taxed income and topped up afterwards. This achieves a similar end result for higher earners, full relief at their marginal rate, but automatically through payroll, without needing to file a Self Assessment claim.
There's an annual allowance to be aware of too. Pension contributions attracting tax relief are capped at £60,000 a year for most people, tapered down for very high earners in ways this tool doesn't attempt to work out for you. If you're contributing anywhere close to that limit, it's worth checking your specific position carefully rather than relying on estimates alone.
It means you pay in 80% of the gross amount you want in your pension, and your provider automatically claims the remaining 20% from HMRC and adds it, so an £800 payment becomes £1,000 in your pot.
No. Under relief at source, only the basic 20% is added automatically; the extra relief up to your marginal rate has to be claimed separately through Self Assessment.
You pay £800 upfront, the provider adds £200 in basic relief to reach £1,000, and you can then reclaim a further £200 via Self Assessment, bringing your true net cost down to £600.
They're entitled to 45% relief overall. On a £1,000 contribution that means £200 added automatically and up to £250 more reclaimable via Self Assessment, for a net cost of around £550.
£60,000 a year for most people, though it's tapered down for very high earners. Contributions attracting tax relief above your allowance can trigger a tax charge, so check your own position if you're near the limit.
Not necessarily. Many workplace schemes use a net pay arrangement instead, where your contribution comes out of your salary before tax is worked out, giving higher earners full relief automatically without a Self Assessment claim.
Through your Self Assessment tax return, by declaring your gross pension contributions in the relevant section; HMRC then adjusts your tax bill or issues a refund for the extra relief above the basic 20%.
You could, under a relief-at-source scheme, since the extra relief isn't claimed for you automatically. You may need to contact HMRC directly or register for Self Assessment to claim it.
These results are estimates for general guidance and are not financial advice. Always confirm important figures with an official source.
Rates last reviewed: 2 October 2026 · Built around the 2026/27 UK tax year
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