A question we hear fairly regularly and the answer is yes.
If you are sent a tax return to complete then you must enter details of all income received no matter how trivial or whether it is taxed before you receive it.
This means that all interest received net of tax and dividends received must be included.
Some of my income arises from assets held in joint names and the other party completes tax returns, do I also need to enter the same details?
Again, the answer is yes.
The most common situation is married couples having joint accounts, but in all cases where an asset is held in joint names then your share must be entered on your tax return.
A common error is one party entering all of the income and the other party entering nil, usually because one pays a higher rate of tax than the other.
The usual entry required is a 50/50 split unless the asset is actually not owned 50/50 in which case a form can be submitted to HMRC to elect for the income to be reported in the actual ownership ratios.