The phrase 'fixed fee' appears on a lot of consulting websites. What it means in practice varies considerably. Some firms quote a fixed fee for a discovery phase and then bill hourly for everything after. Others fix the fee but leave the scope vague enough that almost any additional request becomes a billable extra. This article explains how a genuine fixed-fee model works, what you should expect from it, and how to tell the difference between a real flat fee and one that is fixed in name only.
What a fixed scope actually means ¶
A fixed-fee engagement starts with a written scope document that defines, in plain language, what will be delivered, by when, and by whom. The scope is agreed before any work begins and before any fee is charged. If the consultant cannot tell you exactly what you will receive at the end of the engagement, the fee is not really fixed. It is an estimate with a ceiling, which is a different thing.
How scope changes are handled ¶
In a genuine fixed-fee model, if the consultant underestimates the work required, that is the consultant's problem. The fee does not change. The only time a fee should change is if the client requests something that was not in the original scope. In that case, the additional work should be quoted separately, in writing, before it begins. A consultant who adds charges without a written change request is not operating a fixed-fee model.
When fixed-fee works well ¶
Fixed-fee engagements work best when the output is clearly definable: a roadmap document, an audit report, a vendor comparison matrix. They are less well-suited to open-ended advisory relationships where the work evolves week to week. If you need ongoing strategic input rather than a specific deliverable, a retainer model may be more appropriate, though you should still expect a clear description of what that retainer covers.
Questions to ask before signing ¶
Before signing a fixed-fee consulting agreement, ask: what exactly will I receive at the end? What is not included? What happens if the project takes longer than expected? Who will do the work? What is the process if I want to add something? The answers to those questions will tell you whether the fixed fee is genuine or whether it is a marketing label on a standard hourly arrangement.
The post-delivery period ¶
A fixed-fee engagement should not end the moment the document is delivered. A reasonable post-delivery support window, typically 30 days, allows you to ask clarifying questions, request minor adjustments, and flag anything that needs revisiting. If a consultant delivers a report and then bills for every subsequent email, that is worth knowing before you sign.
If you are evaluating consulting firms and want to understand exactly how our fixed-fee model works, the best starting point is a free 45-minute discovery call. We will walk you through the scope process and answer any questions before you commit to anything.