Key facts: Pensions: tax relief in (20–45%), employer contributions, locked until 55 (57 from 2028), 25% tax-free out, rest taxed. ISAs: taxed money in, everything tax-free out, access any time, £20,000 annual allowance. The near-universal first move: employer match before everything — it's an instant 100% return.
Two wrappers, mirrored taxes
Pensions defer tax: relief boosts contributions now (£100 costs a basic-rate taxpayer £80, a higher-rate taxpayer £60), growth compounds untaxed, withdrawals are taxed later — but a quarter comes out tax-free, and most people pay lower rates retired than working. That arbitrage is the pension's engine. ISAs prepay tax: no relief going in, but growth and every withdrawal are clean, forever, with no access age. Same investments inside either — the wrapper choice is purely about tax timing and when you'll need the money.
The practical order
1. Employer match: contribute whatever your scheme matches — doubling money instantly beats every alternative. 2. High-interest debt and an emergency fund (in cash, not either wrapper — see why in our ISA guide's cash section). 3. Goals before ~57 → ISA: house deposits, career breaks, school fees — pension money is simply unreachable. 4. Retirement money → pension first, especially for higher-rate taxpayers, whose 40%+ relief is very hard to beat; under-40s saving for a first home should weigh the Lifetime ISA's 25% bonus here too. 5. Beyond allowances or wanting optionality → both — a retirement funded from a pension and an ISA lets you manage taxable income in retirement elegantly.
Where the answer flips
Basic-rate taxpayers without employer match face a closer call — 20% relief in versus taxed-but-flexible ISA is nearly a wash on pure tax, so access preferences decide. The self-employed (no match, but full relief — see self-employed pensions) still usually favour pensions for retirement money. High earners near pension allowances top up ISAs; anyone who might need the money early must respect the lock. And retirement-age savers find the distinction dissolving — pensions become accessible and the comparison becomes about estate and tax management.
Allocating your actual pounds
The right split depends on tax band, employer scheme, goals and timelines — an adviser will run your numbers across both wrappers. Find an investment adviser through Nesto — free, no obligation.
Frequently asked questions
Which is better, pension or ISA?
For retirement money with employer match or higher-rate relief: pension. For anything needed before ~57: ISA. Most people correctly hold both.
Why is the employer match so important?
It's an immediate 100% return before any market growth — no other mainstream option compares. Always capture the full match.
When can I access each?
ISAs any time. Pensions from 55 (57 from 2028), with 25% typically tax-free and the rest taxed as income.
What about the Lifetime ISA?
For 18–39s: a 25% government bonus toward a first home or age-60 savings — a strong supplement, with penalties for other withdrawals.