Because there are many different categories of expense, it can often be confusing which expenses are suitable to claim, and for many people the question of how those claims might affect other financial returns on your work is a confusing one.
The legislation covering expenses is complex and many edge cases and exceptions exist, so we would recommend consulting a professional for anything unusual and for any substantial purchase where claiming or not claiming them will significantly affect your bottom line, rather than risk being wrong.
However, there are some basic guidelines for contractors working under the ICS Umbrella solution.