PIM2070 - Deductions: main types of expense: advertising expenses
Revenue expenses of advertising for new tenants are allowable; for example, the cost of placing adverts in newspapers. But the landlord cannot deduct the cost if it is capital expenditure; for example, expenditure on permanent signs or other permanent equipment for displaying vacancy details.
The expenses of advertising property to buy or sell is also capital expenditure and not allowable as a deduction for IT purposes. Such expenditure may possibly be taken into account for CGT purposes when the property is sold (for detailed guidance see the CG manual).