An engagement fee is an upfront charge for starting an adviser engagement. Whether it is separate from other charges, refundable or credited against a later payment depends on the agreed terms.
Identify the work covered by the payment and when it becomes payable. Check how it interacts with any retainer, success fee and expenses.
Ask what happens if the engagement changes or ends before the proposed sale completes. The answer should come from the agreement, not an assumption about how adviser engagements normally work.
See comparing adviser proposals for questions about scope, changes and written engagement terms.