If you are resident in the UK (live here) and are domiciled in the UK (e.g. born here) then you will be taxable in the UK on worldwide income. As a basic idea, if you are not resident in the UK then you will only be subject to UK tax on income arising in the UK.
As with all of our tax tips and web pages this information is necessarily summarised and of a general nature. If you would like detailed specific advice please contact us.