ISAs, Junior ISAs (JISA) and Pensions all have an annual allowance set by the government, as they are tax efficient accounts.
The annual ISA allowance is £20,000.
The annual JISA allowance is currently £9,000.
The annual allowance for SIPPs (Self Invested Personal Pensions) is the lower of £40,000, or as much as you earn in that tax year.
Your General Investment Account (GIA) does not have an annual allowance, meaning it is subject to capital gains tax. The threshold for this is quite high, so the average investor might not ever get near to the threshold - however we must stress that this is down to your own individual tax circumstances. CIRCA5000 cannot give tax advice, if you are unsure please seek financial advice or speak to your accountant.
It is important to note that it is your responsibility to make sure you do not exceed your annual tax allowances. Please seek advice from a professional if you need advice on tax.