A rental bond is a security deposit paid by the tenant at the start of a tenancy. It is held by the RTA and is paid back to the tenant at the end of the tenancy provided no money is owed for rent, damages or other costs.
It is not compulsory to take a Bond – however, it is common practice for agents to do so, as it provides a kind of insurance to the owners in case any money is owed at the end of a tenancy.