There are a number of expenses specifically disallowed by section 81, such as rent of private accommodation.
Where expenditure relates to both business and private use, only that part which relates to your business will be allowed. Examples of such expenditure are rent, electricity, telephone charges etc., where the premises involved is used partly for business and partly for private purposes. These expenses will need to be apportioned to exclude the private use.
Unless this private accommodation was specifically used for business (place to see clients) then no, you would not claim the expense.
The percentage of the place used for business only (an office space in the home). If the room was 10% of the whole and used just for business then 10% would be applied.
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