Pension or ISA: which is actually better for retirement?
A pension gives tax relief going in and taxes most of what comes out. An ISA is funded from taxed income and pays out…
See the tax relief the government adds to what you pay in - for the 2026/27 tax year.
Enter your own contribution from take-home pay. Basic-rate (20%) relief is added automatically (“relief at source”).
Total into your pension
You pay in - the rest is tax relief
Claim back via Self Assessment
As a taxpayer you can reclaim a further through your tax return - it does not go into the pension automatically.
Over the annual allowance
Your gross contribution exceeds the annual allowance for . The excess may attract an annual allowance charge unless you carry forward unused allowance.
Estimate only. Relief depends on your full income and pension scheme type.
For every £1 that lands in your pension, you fund and tax relief covers the rest.
After years at growth, contributing gross a year could be worth about - roughly of that is from tax relief alone.
| Scenario | You pay | Into pension | Reclaim | |
|---|---|---|---|---|
Enter what you pay in and your income, and the tool above estimates the basic-rate relief added at source plus any higher or additional-rate relief you can reclaim. Read on for the formula, worked examples for a basic and higher-rate taxpayer, the 2026/27 rates, and the mistakes that cost people the most.
Pension tax relief is the government's way of refunding the income tax you already paid on money you choose to save for retirement. The principle is simple: pension contributions should come out of untaxed income. Because most people pay in from their net (post-tax) pay, HMRC tops the pot back up to the gross amount.
There are two delivery methods, and which one you have changes how the relief reaches you:
The plain-English formula for relief at source is:
Gross contribution = Net contribution ÷ 0.80
Basic-rate relief added = Gross contribution − Net contribution
So for every £80 you pay in, the provider reclaims £20 and £100 lands in the pension. If you are a higher-rate taxpayer, you can claim a further 20% of the gross figure; an additional-rate taxpayer can claim a further 25%. That extra slice does not go into the pension automatically - it comes back to you through your tax return or tax code, which is the single most overlooked part of the system.
The key idea behind higher-rate pension tax relief is that the contribution extends your basic-rate band. A £10,000 gross contribution pushes the point at which you start paying 40% tax up by £10,000, so more of your income is taxed at 20% instead of 40%. That mechanical effect is why the relief is worth your top rate of tax, not a flat 20%.
How much you get back depends on the highest rate of income tax you pay in England, Wales or Northern Ireland for 2026/27:
Scotland is different, and this calculator flags it. Scottish taxpayers have their own income tax bands (starter 19%, basic 20%, intermediate 21%, higher 42%, advanced 45% and top 48% for 2026/27), so the relief you can claim follows your Scottish marginal rate. A Scottish intermediate-rate taxpayer, for example, can claim 1% extra above the 20% given at source. The Personal Allowance of £12,570 is UK-wide, but the rates that drive your relief are not. If you pay Scottish income tax, use our Scotland tax calculator alongside this one to confirm which band your contribution actually reduces.
This is where real money gets left behind. The basic 20% is automatic on relief-at-source pensions, but the higher or additional-rate slice is not - you have to ask for it. There are three routes:
Workplace schemes run on a net pay arrangement give full relief automatically, so there is nothing to reclaim - but salary sacrifice works differently again, and it is worth understanding which one you are in before you assume relief is missing.
Relief is generous but not unlimited. The annual allowance caps the total going into your pensions each year that can attract relief, and it is tapered for very high earners. You also cannot get relief on personal contributions above 100% of your UK relevant earnings in the year. The mechanics of the cap, carry-forward of unused allowance and the taper for high earners are detailed enough to deserve their own tool - work the limit out with our pension annual allowance calculator before you make a large one-off payment. This page keeps to the relief maths; the allowance page owns the contribution-limit question.
The tool takes your contribution and income and applies the relief-at-source method by default. It grosses up your net payment by dividing by 0.80, shows the basic-rate relief the provider reclaims, then checks your income against the 2026/27 thresholds to estimate any higher or additional-rate relief you can claim back. If you tell it you are in a salary sacrifice or net pay scheme, the relief is already in your figures, so it shows the marginal-rate saving rather than a separate reclaim. Treat the output as a guide - your tax code, other income and pension scheme rules can all shift the exact number.
Take Priya, a teaching assistant earning £28,000, who pays £160 a month into a personal pension. That is a net contribution of £1,920 over the year.
Priya is a basic-rate taxpayer, so 20% is the full relief. Her £1,920 becomes £2,400 in the pot, and there is nothing extra to claim.
Now take James, a project manager earning £60,000, who pays £8,000 net into his SIPP across the year.
James gets £4,000 of relief in total - 40% of the gross. The £10,000 in his pension has cost him just £6,000 net once the reclaim arrives. If he never files for the higher-rate portion, he loses that £2,000 every year it goes unclaimed.
One more, framed around the £100,000 trap. Daniel earns £104,000 and is losing Personal Allowance to the taper (£1 of allowance for every £2 of income over £100,000). A £4,000 gross pension contribution cuts his adjusted income to £100,000, restoring £2,000 of Personal Allowance. Combined with the 40% relief on the contribution itself, the effective relief on that band of income can reach roughly 60%. That is the highest-value relief in the system, and it is why a well-timed contribution near £100,000 is worth checking carefully.
| Item | 2026/27 value |
|---|---|
| Personal Allowance (UK-wide) | £12,570 |
| Basic-rate band (20%) | up to £37,700 of taxable income |
| Higher-rate threshold (40% starts) | £50,270 of total income |
| Additional rate (45% starts) | above £125,140 |
| Relief given at source | 20% (gross = net ÷ 0.80) |
| Extra relief for higher-rate | a further 20% (40% total) |
| Extra relief for additional-rate | a further 25% (45% total) |
| Personal Allowance taper | −£1 for every £2 over £100,000 |
Figures are checked for the 2026/27 tax year. Scotland sets its own income tax rates and bands, so Scottish taxpayers claim relief at their Scottish marginal rate. Confirm the official position at gov.uk pension tax relief and the plain-English guidance from MoneyHelper.
These two routes can produce a similar pension pot but feel completely different on your payslip. With relief at source you pay in from net pay and the relief is added or reclaimed afterwards. With salary sacrifice you give up part of your gross salary in exchange for an employer pension contribution, so you never pay income tax or National Insurance on that slice - and your employer saves NI too, which they may add to your pot.
The National Insurance saving is the part relief at source cannot match. For a higher-rate employee paying 2% NI above the upper earnings limit the gap is smaller, but for a basic-rate employee paying 8% NI the saving is meaningful. Because the mechanism, payslip effect and NI maths differ, we keep that comparison on the dedicated salary sacrifice calculator. If your pension sits inside a self-invested wrapper, our SIPP calculator helps you project the pot the relief is feeding, and the broader pension calculator brings contributions and growth together for retirement planning.
These figures are estimates for guidance only and not personal tax or financial advice. Your scheme rules, tax code and other income can change the result - check with HMRC or a qualified adviser before acting on a large contribution.
Pension tax relief means a contribution costs you less than it adds. At the basic rate, £100 in your pension costs £80; at higher rate it can cost £60, and in the £100,000–£125,140 band where the Personal Allowance tapers, the effective cost can be as little as £40.
The critical practical point: higher-rate relief is not automatic. If your scheme operates relief at source, only basic-rate relief is added by the provider — the rest must be claimed from HMRC, through Self Assessment or by contacting them. Large numbers of higher-rate taxpayers never claim it and simply lose the money.
Once you know your relief, plan the wider picture with our pension calculator for retirement projections, confirm your contribution headroom with the pension annual allowance calculator, and compare delivery methods using the salary sacrifice calculator or model a self-invested pot with the SIPP calculator.
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