Damage to the property above normal wear and tear
Deductions may be made or the deposit retained in full if there has been damage above normal wear and tear to the property. Normal wear and tear occurs where deterioration occurs over a period of time due to ordinary and reasonable use of the premises.
Normally you are not required to get professional cleaners but before leaving you should clean the property, remove all your belongings, dispose of all rubbish and take photos to show the condition in which it was returned. Ideally you should request a final inspection with the landlord/agent.
If your landlord claims that there has been damage to the property they should provide receipts showing the costs incurred in carrying out repairs.