What is the deal with ISAs?
ISAs are the single most useful tool the UK tax system gives young adults, and most people either do not have one, have the wrong type, or are not using theirs properly. Understanding this family of accounts is one of the highest-value things you can learn.
An ISA (Individual Savings Account) is a tax-free wrapper. Money you put inside it grows without income tax or capital gains tax applying. You get an annual allowance for contributions (currently £20,000 across all your ISAs) and anything you do not use by 5 April that year is gone.
There are four main types of ISA wrappers: Cash ISA (for saving), Stocks and Shares ISA (for investing), Lifetime ISA (for first home or later life), and Innovative Finance ISA (niche, probably ignore). The one you want depends on what the money is for and when you will need it.
For money you might need in the next one to three years — an emergency fund, a wedding, a car — a Cash ISA is the right answer. The rate will be lower than interest rates on normal savings accounts in some years and higher in others, but the tax-free bit means you keep everything you earn on it. However, for most people who are basic rate taxpayers with small levels of savings a cash ISA is completely unnecessary. Basic rate taxpayers get an annual Personal Savings Allowance (PSA) of £1,000 which means they can earn up to £1,000 a year of interest without paying tax on it (at a rate of 5% this would mean £20,000 of savings).
For money you will not touch for five years or more — long-term wealth, a pension supplement, future you — a Stocks and Shares ISA is almost always the right answer. You put the money in, buy a global index fund (or other well-diversified, well-researched options), and leave it alone. Over longer time periods, investments in a diversified portfolio have historically beaten cash savings by a meaningful margin, but they go up and down on the way. That is why the “five years or more” rule exists.
For a first home, the Lifetime ISA (LISA) gets a 25% government bonus on top of what you put in, up to £4,000 per year. If you are 18 to 39 and even thinking about a first home, open one now — even a tiny deposit gets the clock running. The catch is that withdrawing for anything other than a first home or retirement comes with a 25% penalty, which is designed to feel worse than losing the bonus.
The single biggest ISA mistake people make is choosing Cash when they should have chosen Stocks and Shares, because “investing” sounds scary. Over twenty years, the gap between a Cash ISA and a diversified Stocks and Shares ISA is often tens of thousands of pounds. That is the cost of being cautious with money you were never going to spend.
What you can actually do this week
- If you do not have any ISA, open a Stocks and Shares ISA with a low-fee platform (Vanguard, Trading 212, InvestEngine and similar) and put in £25 as a global index fund. You can add more later. The point is to open the account.
- If you have a Cash ISA holding long-term money, read up on Stocks and Shares ISAs before April to see if you should switch a portion.
- If you are under 40 and saving for a first home, open a LISA alongside whatever else you have.