2026/27 UK Stocks & Shares ISA rules
The allowance is simple. The provider choice is not. Use this as the Stocks & Shares ISA rules check, then model platform, dealing, and FX costs before opening or transferring.
Short answer
For the 2026 to 2027 tax year, the adult ISA allowance is £20,000. A Stocks & Shares ISA uses that same allowance. GOV.UK says you can use the allowance in one ISA or split it across multiple ISA accounts. The Junior ISA limit is £9,000.
Rules
| Rule | 2026/27 position | What it means for Stocks and Shares ISAs |
|---|---|---|
| Adult ISA allowance | £20,000 | This is the total subscription limit across adult ISAs for the tax year, including any Stocks and Shares ISA contributions. |
| Tax year | 6 April 2026 to 5 April 2027 | Unused allowance is a tax-year allowance, not something to carry forward into a later Stocks and Shares ISA contribution. |
| Splitting allowance | Allowed across multiple ISA accounts | You can split the allowance across account types instead of putting everything into a Stocks and Shares ISA. |
| Junior Stocks and Shares ISA allowance | £9,000 | This is separate from the adult allowance and applies to eligible children. |
| Lifetime ISA annual payment | Up to £4,000 within the £20,000 ISA allowance | The Lifetime ISA limit is a sub-limit, not an extra £4,000 on top of the adult allowance. |
Fee traps
A £20,000 allowance does not make every Stocks and Shares ISA provider comparable. A platform can look cheap for ETFs and expensive for funds, or free for GBP trades but costly for regular US share buying.
The calculator models wrapper-level platform, dealing, and FX costs. It does not model fund ongoing charges, spreads, investment performance, tax advice, or provider promotions unless they are explicitly included.
Stocks and Shares ISA
If you are using a Stocks & Shares ISA, start with the holding you actually expect to own: funds, ETFs, individual shares, or a mix. Then check whether your provider charges a percentage platform fee, a flat account fee, dealing fees, and FX fees.
FAQ
The adult ISA allowance for the 2026 to 2027 tax year is £20,000. A Stocks & Shares ISA uses that same allowance. The tax year runs from 6 April 2026 to 5 April 2027.
Yes. GOV.UK says you can save up to £20,000 in one account or split the allowance across multiple ISA accounts in the same tax year, including a Stocks & Shares ISA.
The Junior ISA limit for the 2026 to 2027 tax year is £9,000. Junior Stocks & Shares ISA fees and provider availability are separate questions from the allowance.
No. The allowance tells you the maximum subscription. The cheapest provider depends on your balance, monthly contributions, investment type, dealing pattern, and FX use.
Sources
Educational information only, not financial advice, tax advice, or a recommendation to open, transfer, buy, sell, or hold any investment.