ISA allowance calculator
Enter what you have paid into each ISA this tax year. The calculator splits the £20,000 adult allowance across your Cash ISA, Stocks & Shares ISA and Lifetime ISA, adds the 25% LISA bonus, prices the early-withdrawal charge and tracks the £9,000 Junior ISA cap separately.
The £20,000 adult allowance is one shared pool: Cash, Stocks & Shares and LISA deposits all draw from it, with at most £4,000 going into a Lifetime ISA. The Junior ISA has its own £9,000 cap per child and does not use your adult allowance.
How much can you put in an ISA?
For 2026/27 you can pay up to £20,000 into ISAs in total, of which at most £4,000 may go into a Lifetime ISA. Each child has a separate £9,000 Junior ISA allowance. These limits are frozen to 2030/31.
| ISA type | Annual limit | Notes |
|---|---|---|
| Cash ISA | Up to £20,000 (shared) | Part of the single adult allowance |
| Stocks & Shares ISA | Up to £20,000 (shared) | Part of the single adult allowance |
| Innovative Finance ISA | Up to £20,000 (shared) | Part of the single adult allowance |
| Lifetime ISA | £4,000 | 25% government bonus; counts inside the adult allowance |
| Junior ISA | £9,000 | Per child, separate from the adult allowance |
The limits, the shared allowance and the LISA bonus come from gov.uk guidance on how ISAs work, the Lifetime ISA guidance and the Junior ISA guidance.
Worked ISA splitting examples
These examples show how deposits across accounts draw from the one shared adult pool, and what the government bonus adds to a full £4,000 LISA deposit.
| Cash | S&S | LISA | Junior | Allowance left | LISA bonus |
|---|---|---|---|---|---|
| £20,000 | £0 | £0 | £0 | £0 | £0 |
| £16,000 | £0 | £4,000 | £0 | £0 | £1,000 |
| £12,000 | £5,000 | £4,000 | £9,000 | £0 | £1,000 |
| £15,000 | £8,000 | £4,000 | £0 | £0 | £1,000 |
The LISA bonus and the early-withdrawal charge
The government adds 25% to every Lifetime ISA deposit, up to a maximum bonus of £4,000 a year. A full £4,000 deposit earns £1,000 of bonus.
If you withdraw before age 60, except in cases of terminal illness or buying a first home under the rules, the government charges 25% of the amount withdrawn. Because the charge also claws back bonus money you never received, withdrawing £1,000 costs £250. That is the £200 bonus you got on the £800 contribution element, plus £50 on top. The extra £50 is about 6.25% of your own money taken out.
| Withdrawal | Charge (25%) | You receive |
|---|---|---|
| £500 | £125 | £375 |
| £1,000 | £250 | £750 |
| £4,000 | £1,000 | £3,000 |
This focused estimate excludes transfers between ISAs, which do not use allowance, and previous-year LISA withdrawals. It is not financial advice.
Common ISA allowance questions
Is the ISA allowance shared between accounts?
Yes. You get one £20,000 allowance per tax year for all adult ISAs combined. You could put £20,000 in a Cash ISA, £10,000 in Cash and £10,000 in Stocks & Shares, or £16,000 in Cash and £4,000 in a LISA, but never more than £20,000 in total.
How much bonus does a Lifetime ISA pay?
25%. Every £4,000 deposited earns a £1,000 government bonus, and deposits are capped at £4,000 a year, so the maximum bonus is £1,000 a year.
What happens if I withdraw from a LISA before 60?
Outside the first-home and terminal-illness exceptions, the government takes 25% of the withdrawal. On a £1,000 withdrawal that is a £250 charge, more than the bonus you received, so it can leave you worse off.
Does a Junior ISA use my allowance?
No. Each child has their own £9,000 Junior ISA allowance, separate from the £20,000 adult allowance. Anyone can contribute, but the child cannot access the money until 18.
Does the ISA allowance reset?
Yes, each tax year on 6 April. Unused allowance does not roll over, so a year where you deposit nothing still loses that year's £20,000.
Will the ISA allowance change?
The £20,000 allowance is frozen to 2030/31. From 6 April 2027 the government has announced changes to how under-65s can split the allowance between Cash and Stocks & Shares ISAs, so check gov.uk before then.