A landlord may seek to deduct reasonable cleaning costs where the property was left significantly less clean than it was at the start of the tenancy, beyond normal wear and tear. They should be able to explain the deduction and provide appropriate evidence, such as check-in and check-out photographs, an inventory, invoices or receipts. You can ask for an itemised statement and challenge an unreasonable deduction with the Residential Tenancies Board (RTB). The RTB or a solicitor would ultimately assess whether the charge was justified based on the individual tenancy and evidence.