Hi,
A non-UK resident person, is taxable on savings and investment income in the UK, which is treated as 'disregarded income'. The effect of this is that the liability of a non UK resident in respect of savings and investment income, is limited to the Income Tax deducted from it, or treated as deducted or paid in respect of it.
To report this income would require the completion of a self assesment tax return, in which you would declare the savings and dividends and that you are not resident in the UK. You should also consider the doublt taxation agreement, if there is one, between the UK and your country of residence.
Collection Tax treaties
Thank you.