ISA Calculator
Estimate the tax-free growth of your Stocks & Shares ISA or Cash ISA. See how the £20,000 annual allowance compounds over time - and how much Capital Gains Tax you save vs a standard investment account.
Frequently Asked Questions
What is the ISA allowance for 2026/27?
Each UK adult has a £20,000 ISA allowance for the 2026/27 tax year (6 April 2026 to 5 April 2027). This is a 'use it or lose it' allowance - any unused allowance does not carry forward to the next tax year. A couple can invest up to £40,000 combined per tax year.
What is the difference between a Stocks & Shares ISA and a Cash ISA?
A Cash ISA works like a savings account - your money earns interest and the ISA wrapper means that interest is tax-free. A Stocks & Shares ISA lets you invest in funds, shares, bonds, and ETFs - all growth and income inside the ISA is tax-free. Over 5+ years, a Stocks & Shares ISA in a global index fund has historically significantly outperformed Cash ISAs, though it carries investment risk.
Can I have both a Stocks & Shares ISA and a Cash ISA?
Yes - you can subscribe to one of each type of ISA per tax year, splitting your £20,000 allowance between them. For example, £15,000 in a Stocks & Shares ISA and £5,000 in a Cash ISA. You cannot pay into two ISAs of the same type in the same tax year with different providers.
What are the best Stocks & Shares ISA providers in the UK?
For low-cost index fund investing: Vanguard Investor (0.15% platform fee, excellent for Vanguard funds), Trading 212 (zero commission, free ISA), InvestEngine (managed and DIY, very low fees). For wider fund choice: AJ Bell, Hargreaves Lansdown. For beginners: Trading 212 or Vanguard. Always compare annual fees, especially for larger portfolios where flat-fee platforms like Interactive Investor become cheaper.
What happens to my ISA if I die?
From April 2024, ISAs retain their tax-free status for up to 3 years after the holder's death (known as 'continuing ISAs'). Additionally, a spouse or civil partner can inherit the ISA allowance as an 'Additional Permitted Subscription' (APS) - effectively meaning they can inherit the full ISA pot tax-free.
Can I withdraw money from my ISA whenever I want?
For most ISAs, yes - you can withdraw at any time with no tax or penalty. Some ISAs are 'flexible', meaning you can withdraw and re-deposit within the same tax year without it counting against your allowance. The exception is the Lifetime ISA (LISA): withdrawals for purposes other than a first home purchase or retirement (after age 60) incur a 25% government penalty.