What type of fee structure is a nonreturnable advance to a consultant?

The type of fee structure referred to as a nonreturnable advance to a consultant aligns with the concept of a retainer. A retainer is typically an upfront fee paid to secure a consultant's services, ensuring that they are available for a certain period or for a specific project. This fee is often nonrefundable, meaning that once it is paid, the consultant is compensated for making themselves available, regardless of whether the client ultimately uses their services to the full extent anticipated.

In contrast, an advance payment can be seen as a partial payment made towards a service or project, which may or may not be refundable depending on the terms agreed upon. Consulting fees generally refer to the payments made for the services provided, and a fixed fee is a set amount agreed upon for a specific service or project. Neither of these options encapsulates the nature of a retainer, as they imply different financial arrangements throughout the course of the consulting engagement.