Pension tax relief calculator

Work out how much your pension contribution is really worth once tax relief is added, whether you're on relief at source or net pay, and how much a higher or additional-rate taxpayer can claim back.

Figures for the 2026/27 tax year. Last reviewed 01-09-2026.

How pension tax relief actually works

Every pound you put into a pension gets tax relief at your marginal rate, because pension contributions are meant to come out of income before tax, not after it. How that relief reaches you depends on your scheme's method.

Under relief at source, you pay money into the pension after tax has already been taken from your pay. Your provider then claims basic-rate relief (20%) from HMRC and adds it to your pot automatically, grossing up whatever you paid by dividing by 0.8. Pay in £800 and your pot receives £1,000. If you're a higher or additional-rate taxpayer, that 20% top-up isn't the end of it — the rest of your relief has to be claimed separately through self-assessment.

Under net pay, your employer deducts the contribution from your gross salary before income tax is calculated at all. You get full relief at your marginal rate immediately, automatically, with nothing to claim back. The trade-off is that net pay schemes don't add anything for non-taxpayers, since there's no tax to relieve in the first place.

A worked example

Take someone earning £70,000 a year who pays £4,000 net into a relief-at-source pension. Their provider grosses this up to £5,000 in the pot (£4,000 ÷ 0.8), adding £1,000 of basic-rate relief automatically. Because £70,000 puts them well into the 40% band, they're entitled to relief at 40% on the full £5,000 — £2,000 in total. £1,000 of that has already landed in the pot; the remaining £1,000 only arrives if they claim it through self-assessment. Their true cost, after that claim, is £3,000 for a £5,000 contribution.

Compare that with the same £4,000 contribution made through a net pay scheme instead. There, the £4,000 comes straight off gross salary before tax, so the full 40% relief — £1,600 — is automatic. Nothing to claim, but the pot only holds £4,000 rather than £5,000, because net pay never grosses anything up. The trade-off between the two methods is really about timing and effort, not about how much relief you're ultimately entitled to at a given marginal rate.

Claiming the extra relief via self-assessment

If you're a higher or additional-rate taxpayer on a relief-at-source scheme, the 20% your provider adds is only ever the starting point. You claim the rest by declaring your gross pension contributions on your self-assessment tax return, in the section for pension contributions — HMRC then extends your basic-rate band by the gross amount, which pulls some of your income down from 40% (or 45%) to 20%, and either refunds the difference or adjusts your tax code.

You don't need to be self-employed to do this. Anyone who pays higher or additional-rate tax and contributes to a relief-at-source pension can register for self-assessment for this purpose alone. If you'd rather not file a return, you can sometimes ask HMRC to adjust your tax code instead by writing to them or using the online service, though a return usually gives a cleaner, faster result for larger claims.

There's a practical trap here: people forget to claim year after year, effectively donating the higher-rate portion of their relief to HMRC. You can usually go back up to four tax years to claim relief you missed, so it's worth checking old contributions if this is the first time you've worked this out.

The Scottish tax position

Scottish taxpayers have more income tax bands than the rest of the UK — starter, basic, intermediate, higher, advanced and top — and the higher rates (42%, 45% and 48%) kick in at lower income levels than rUK's 40% and 45%. Relief-at-source pensions still only add the UK basic rate of 20% automatically, based on the rUK rate, regardless of where you live. Scottish intermediate, higher, advanced and top-rate taxpayers therefore have relief to reclaim above 20% too, just as rUK higher-rate taxpayers do, worked out against the actual Scottish bands they fall into.

Net pay schemes don't have this quirk, because relief there is simply the tax you'd otherwise have paid on that slice of income under whichever bands actually apply to you.

Common mistakes people make

The most common one is assuming a £5,000 pension contribution costs £5,000. For anyone paying tax, it doesn't — the true cost is always lower once relief is accounted for, and can be as low as 55p per £1 for an additional-rate taxpayer under relief at source, once the reclaim is actually made.

The second is forgetting that relief at source's automatic 20% is a floor, not a ceiling. If you're a higher-rate taxpayer and you never file a self-assessment return, you're leaving real money on the table every year, not just once.

The third is confusing pension tax relief with the annual allowance. Relief brings the cost of a contribution down; the annual allowance (£60,000 for most people in 2026/27) caps how much can go in before a tax charge applies. This calculator handles relief only — check your allowance separately if you're contributing large amounts.

Frequently asked questions

Do I automatically get higher-rate tax relief on my pension?

Only under a net pay scheme, where relief is automatic at your full marginal rate. Under relief at source, your provider only ever adds the basic 20% automatically — anything above that has to be claimed through self-assessment, or it simply isn't paid.

How do I know if my pension uses relief at source or net pay?

Check your payslip or ask your payroll or pension provider. As a rule of thumb, most personal pensions and SIPPs use relief at source, while many (though not all) workplace pensions use net pay — but this varies by scheme, so it's worth confirming rather than assuming.

What if I don't pay enough tax to use all my relief?

Relief-at-source schemes add the 20% basic-rate top-up even to non-taxpayers and low earners, up to certain contribution limits, because the relief is added at source regardless of your actual tax bill. Net pay schemes only relieve tax you'd actually have paid, so a non-taxpayer gets no boost at all under net pay — this is one of the few situations where relief at source can genuinely leave you better off.

Is there a deadline for claiming higher-rate relief via self-assessment?

You can usually claim relief for the current tax year and go back up to four further tax years, in line with HMRC's normal time limit for claims. After that, unclaimed relief is generally lost, so it's worth checking past contributions if you haven't claimed before.

Does this calculator account for the annual allowance?

No — this calculator works out the relief on a contribution you specify, not whether that contribution fits within your allowance. Most people have a £60,000 annual allowance in 2026/27, though it tapers down for very high earners and is capped lower if you've already flexibly accessed a pension (the Money Purchase Annual Allowance).

Does the Scottish rate change how much relief I get?

It changes how much you're entitled to overall — Scotland's intermediate, higher, advanced and top rates differ from rUK's — but relief-at-source providers still only add the UK basic rate of 20% automatically. Scottish taxpayers on intermediate rate and above need to reclaim the difference themselves, in the same way rUK higher-rate taxpayers do.