An ISA does not automatically exempt wealth from Zakat. A cash ISA is assessed as cash; a stocks-and-shares ISA is assessed according to its investments and the approach you follow. A Lifetime ISA’s access conditions may require additional consideration. Count each account only once.
Match the wrapper to its contents
An ISA is an account arrangement with UK tax rules. It can hold very different assets. Begin with a statement separating cash, shares and funds. Assess those assets using their relevant methods, rather than giving every ISA one blanket treatment.
A stocks-and-shares ISA may include uninvested cash. If the statement’s total already includes that cash, do not add it again to your current account or cash line.
Entering an ISA in the calculator
Use the ISA field for an eligible amount not already included elsewhere. Alternatively, enter cash ISA money under cash and investment ISA money under shares. If you have calculated a known eligible proportion externally, enter that amount once.
The calculator’s long-term investment option includes a proxy method. Do not apply a proxy twice by first reducing the ISA value and then asking the calculator to reduce it again.
A split-account example
A person holds a £3,000 cash ISA and an investment ISA worth £8,000. If they use full value for the investments, eligible ISA assets are £11,000. If their supported investment assessment identifies £2,000 of eligible underlying assets, the combined eligible amount is £5,000.
These amounts join the rest of their wealth before permitted deductions and the nisab and hawl checks. The tax wrapper does not remove those steps.
Lifetime and restricted-access accounts
Do not automatically subtract a possible withdrawal charge from every Lifetime ISA. Establish ownership, accessibility and the ruling you follow. A future charge that might arise is different from a liability already incurred. Junior accounts also involve ownership and the school-specific treatment of children’s wealth.
Sources & calculation method
These sources inform this guide. A linked source does not endorse this site, and its publication date may differ from this page’s update date.
- National Zakat Foundation: understanding and calculating Zakat
- National Zakat Foundation: pension types and asset proportions
Scholarly methods can produce different results. See the method choices that affect a Zakat estimate and our editorial policy. This is educational guidance, not a personal ruling or a claim of named scholarly review.
To cite this guide: “Zakat on ISAs: cash, shares and Lifetime ISAs”, World Aid Network, updated 8 September 2026, https://zakat-calculator.org.uk/zakat-on-isa