rent paid in full

Tenancy Types and Management

I rent a 4 bed house to European Students on a joint and several - They arrive Sept and leave end of Aug - and all know each other . one parent pay on behalf of the others to cut down on their bank charges. Question : as the deposit is now around 4/5k and is placed in a scheme , returned back at end of 12 mth with currancy fluctuations. Can I offer an option to pay up front a years rent there by removing the need for a deposit which for me has been more about loss of rent than damage .
if so can I charge a cleaning fee up front too - there by removing the need for any deposit .

Thank you