Fixed-fee projects that still make money at the end

A fixed-fee project is priced against an estimate: a certain number of hours, a certain cost, a certain target margin. Every hour beyond that estimate comes directly out of your profit unless you charge for it separately. This is the trade the client is implicitly making when they choose fixed fee over hourly: predictability for them, and risk for you, unless the scope is genuinely well defined and well managed.

MarginFence's baseline captures the deal you made: contract amount, estimated hours, internal cost rate, billable rate and target margin. When a client asks for something beyond that scope, logging it converts an abstract 'a bit more work' into a specific number of hours and dollars, calculated against your real cost rate rather than a guess made under time pressure.

For every logged request, MarginFence supports five decisions. Comp absorbs the cost as goodwill. Decline holds the original scope. Trade exchanges the new work for something else already in scope, keeping total hours roughly flat. Charge Recommended applies MarginFence's calculated quote, which holds your target margin on the increment. Charge Custom lets you set your own figure, higher or lower, for a specific commercial reason.

Because each decision updates the project's revised revenue, cost and margin immediately, you do not need to wait until the project closes to see whether it is still profitable. If revised margin has dropped further than you're comfortable with halfway through delivery, that is the moment to start charging for further requests, decline the next one outright, or have a direct conversation with the client about the trend.