What is an ISA?
An ISA, or Individual Savings Account is a ‘wrapper’ in which you can shelter savings and investments from tax. It is not an investment in its own right.
There are significant tax advantages of investing in an ISA- you pay no capital gains tax and no UK income tax on your ISA savings. You don’t need to declare ISAs on your tax return.
You need to be a UK resident to open an ISA.