[1] Its distinguishing feature is that the client or customer pays in advance for professional work to be specified later.
The purpose of a retainer fee is to ensure that the employed reserves time for the client in the future when their services are needed.
A retainer agreement may incorporate other contractual provisions regarding the performance of services, or the parties may potentially enter into additional contracts that define the other terms of their working relationship.
Absent an agreement to the contrary, a retainer fee is refundable if the work is not performed.
In addition to being formally described in a retainer agreement, a client's grant of authority to an attorney may be implied, apparent or usual through the normal practice of the legal professional in providing representation to a client.