Pension or ISA? Where to Put Your Savings
Both shelter your money from tax. The difference is when the taxman takes his cut: pensions give you the break on the way in, ISAs on the way out. For retirement saving the pension usually wins, and the maths shows exactly why and by how much. But ISAs earn their place, and two rule changes coming in 2027 shift the picture for both.
The two deals, side by side
| Pension | ISA | |
|---|---|---|
| Money going in | Tax relief at your rate (20% to 45%), plus employer money in a workplace scheme | From taxed income, no top-up |
| While invested | No UK tax on growth | No UK tax on growth |
| Money coming out | 25% tax-free, the rest taxed as income | All tax-free |
| When you can take it | From 55 (57 from April 2028) | Any time |
| Annual limit | £60,000 (and up to 100% of earnings for your own contributions) | £20,000 across all ISAs in 2026/27 |
The maths: same money, different outcomes
Take £100 of gross pay and a basic-rate taxpayer in both work and retirement. Ignore growth; it multiplies both sides equally.
- Via a pension: the full £100 goes in thanks to tax relief. Coming out, 25% is tax-free and 75% is taxed at 20%, leaving £85.
- Via an ISA: tax first, so £80 goes in. It comes out untouched: £80.
The pension wins by 6.25%, entirely because of the 25% tax-free lump sum. Pay 40% tax now but 20% in retirement, which is common, and the same £100 becomes £85 in the pension against £60 in the ISA, a 42% advantage. Our sums; the pattern holds at any growth rate.
Employer money settles the argument
Inside a workplace pension your employer adds at least 3% of qualifying earnings, and many add more if you do. No ISA gets employer money. Whatever else you decide, contribute enough to take every pound of match before an ISA sees a penny of long-term savings.
When the ISA wins
- You might need the money before 57. A pension is locked until then (55 now, 57 from April 2028). House deposit, career break, emergency fund: ISA territory. A locked-up bargain is no bargain if it forces you into expensive debt at 40.
- You have no earnings to get relief on. Pension tax relief needs earnings (a small £3,600 gross allowance aside). Non-earners with savings to place may find the ISA simpler.
- You expect to pay a higher tax rate in retirement than now. Rare, but it flips the maths.
The Lifetime ISA, the hybrid
If you are 18 to 39, the Lifetime ISA blends the two: pay in up to £4,000 a year (inside the £20,000 total) and the government adds 25%, with tax-free withdrawals from 60, or earlier for a first home (source: GOV.UK). For a basic-rate taxpayer without employer match on offer, a LISA rivals a pension. The catch is the 25% penalty for taking money out early for anything else, which claws back more than the bonus. Self-employed savers in particular often run a pension and a LISA together.
Two 2027 changes worth knowing now
- The cash ISA cap shrinks. From 6 April 2027, under-65s can put at most £12,000 of the £20,000 allowance into cash ISAs; the rest must go to stocks and shares or other non-cash ISAs to use the full allowance (announced at Autumn Budget 2025; source: GOV.UK). Savers holding large cash ISA balances have until 5 April 2027 under the current rules.
- Pensions join inheritance tax. From April 2027, unused pension pots are due to count as part of your estate for inheritance tax, weakening what was a big pension advantage. Our death benefits guide covers the detail.
See what the pension route builds
Put your numbers in our free calculator, including employer contributions, and see your projected pot. No sign-up, assumptions in the open.
Try the calculator →A sensible order for most people
- Workplace pension up to the full employer match.
- An emergency fund in easy-access savings or a cash ISA (three to six months of spending).
- Then by goal: retirement money to the pension for the relief, sooner-than-57 money to an ISA, and a LISA if you are young enough and it fits.
The wrong question is "which is better?". The right one is "when do I need which pound?". Most people end up wanting both.
The Pension Sprout letter
One plain-English pension tip each month, plus what has changed in the rules. No spam, unsubscribe any time.
Sent via MailerLite. See our privacy policy.
This article is for general information only and does not constitute financial advice. The comparisons are illustrations based on 2026/27 tax rules, correct as of July 2026; the 2027 changes described were announced but details can change before they take effect. Tax treatment depends on individual circumstances. For advice tailored to you, speak to a financial adviser regulated by the Financial Conduct Authority (FCA), or get free guidance from MoneyHelper.