Retainer Fee

Definition

A retainer fee is a fixed, recurring amount a client pays in advance to secure ongoing access to a professional's services over a defined period, commonly monthly. In CPA and advisory engagements, retainers provide predictable revenue for the firm and cost certainty for the client, replacing unpredictable hourly billing. The retainer amount is typically scoped to a defined set of deliverables or hours, with additional work billed separately.