How to Maximise Your ISA Allowance 2026/27
Every UK adult gets a £20,000 tax-free ISA allowance each tax year. It resets on 6 April and unused allowance is gone forever. Here's how to make every penny count.
What is the ISA allowance?
An Individual Savings Account (ISA) is a tax wrapper. Any interest, dividends, or capital gains you earn inside an ISA are completely free from UK income tax and capital gains tax. They stay tax-free indefinitely, not just while the money is in the ISA.
The allowance is the maximum you can pay in across all your ISAs in a single tax year (6 April to 5 April). For 2026/27 that's £20,000. You can't carry unused allowance forward. If you only put in £5,000 this year, you can't add an extra £15,000 on top of next year's allowance.
2026/27 ISA facts at a glance
- Annual allowance: £20,000
- Tax year: 6 April 2025 – 5 April 2026
- You can split across multiple ISAs in the same year
- Withdrawals are tax-free (for flexible ISAs, you can replace withdrawals without using more allowance)
- No UK income tax or CGT on interest, dividends, or gains
The four types of ISA
All four types share the same £20,000 allowance, but they work very differently:
| ISA type | Best for | Notes |
|---|---|---|
| Cash ISA | Emergency fund, short-term goals | Earns interest tax-free. Lower long-term returns than investing. |
| Stocks & Shares ISA | Long-term growth (5+ years) | Invest in shares, funds, bonds. Higher expected return, more risk. |
| Lifetime ISA | First home or retirement | 25% government bonus, max £4,000/year. Ages 18–39 only. |
| Innovative Finance ISA | P2P lending | Higher potential returns but higher risk. Less regulated. |
How to split your allowance
Since April 2024, you can contribute to multiple ISAs of the same type in a single tax year, for example two different Cash ISAs or two S&S ISAs. This change gives you more flexibility to chase better rates or use different platforms.
The only constraint: the combined total across all ISAs must not exceed £20,000 in the tax year. If you open a Lifetime ISA, the £4,000 you put in counts towards your £20,000, leaving £16,000 for other ISAs.
Example split: maximising all ISA types
6 tips to get the most from your allowance
Start at the beginning of the tax year
The earlier you invest, the longer compounding works for you. Investing on 6 April rather than 5 April gives your money an extra full year of tax-free growth over a lifetime of saving.
Use it or lose it
Unused allowance is gone when midnight hits on 5 April. Even if you can only put in £50 this year, do it. Small contributions add up, and the tax-free wrapper is the valuable part.
Open a Lifetime ISA if you're under 40
The 25% government bonus is free money: you put in £4,000 and the government adds £1,000, instantly. If you're saving for a first home (under £450,000) or retirement, this beats a regular Cash ISA on any reasonable calculation.
Invest, don't just save
A Cash ISA earning 4% will lose ground to inflation over 20 years. A globally diversified Stocks & Shares ISA has historically returned 7–10% per year over long periods. If you won't need the money for 5+ years, consider investing rather than saving.
Use a Flexible ISA if you might need the money
Many providers offer 'Flexible ISAs', where you can withdraw and replace the money in the same tax year without using more allowance. This is perfect for cash you need access to but still want to shelter from tax.
Consider a Junior ISA for children
Children get a separate £9,000 JISA allowance each year. Investing this from birth means a child could have over £200,000 by age 18, assuming long-term average market returns, without paying a penny of tax on the gains.