Hourly, fixed price, or milestones: pick the failure mode you can live with

Billing arguments start before the invoice. They start when the model does not match how well the work is known.

Hourly

Best when the scope is open: a bug you have not reproduced, a backlog, support after launch.

The failure mode is an unbounded bill. The fix is a log — hours against a task, a short note — and a ceiling you review before it is crossed. “Trust me” is not a log.

Fixed price

Best when the deliverable is small and specific. A defined integration. A closed set of screens.

The failure mode is scope creep. Either the developer absorbs it and rushes, or you get a change request for every sentence. The fix is a written list of what is in and what is out, before work starts. Additions are a new price.

Milestones

Best for a larger build where you want a fixed total but refuse to wait until the end to see software.

The failure mode is a milestone called “phase 1” that nobody can demo. Name the milestone as something you can click: “sign-in and the empty dashboard, on staging.”

A short way to decide

• You know the outcome and it is small: fixed price.
• You know the outcome and it is large: milestones.
• You do not know the outcome yet: hourly, with a check-in.
• There is no end date: hourly or a monthly hour block. See maintenance.

Mixing models is normal. A milestone build, then hourly maintenance, is a healthy sequence. The protection is not the label. It is a sentence that says what done looks like. That sentence lives in the quote, which is why pricing and process are separate pages: one is commercial, one is the sequence.