A security deposit of a minimum of 1.5 x the monthly rental is usually required but differs from agent to agent and with Landlords may be less. Generally agents are managing the property for the landlord and the deposit will be held by agents as stakeholders in a secure client account throughout the tenancy term.
This is held to cover damage, breakages, and any other liabilities under the terms of your tenancy agreement. Please note that under no circumstances can the deposit be used by the tenant to cover rent.
Please make sure you obtain a reciept signed and dated when handing over any money to landlords/agents.