Hi iren,
Please see:
PIM2120 - Deductions: main types of expense: legal and professional costs
Which states 'the expenses incurred in connection with the first letting or subletting of a property for more than one year are capital expenditure and therefore not allowable.
The expenses include, for example, legal expenses (such as the cost of drawing up the lease), agent's and surveyor's fees and commission.
Expenses for a let of a year or less can be deducted.
Thank you.