Welcome to the community @Davesanchez
- Basic = pay capital gains on any investment gain when you later sell the shares, if those gains are more than your cap gains allowance in the year that you sell.
- ISA = pay no tax. This account eventually be priced at 3/month, probably July. Cannot buy certain overseas stocks and funds. Cannot put money into more than one stocks and shares ISA in any single tax year.
These are good places to start reading about ISAs and tax and investing, but the rules of both capital gains tax and ISAs are worth spending a bit of time reading if you’re investing thousands or earning a lot.