How you pay for a build, by the hour or by the project, decides who carries the risk when things take longer than expected. For a founder with a fixed budget, that distinction matters a lot.
The short answer
Hourly billing puts the risk of delays and unclear scope on you: the meter runs while the team figures things out, and the total is unpredictable. A fixed fee puts that risk on the vendor and gives you a number you can plan around. For a defined deliverable, fixed-fee protects your budget better.
How each works
Hourly: you pay for time. Simple, flexible, and uncapped. If the project is vague or the team is slow, your bill grows and you have little control. You are also paying for the hours spent deciding what to build, not just building it.
Fixed fee: you agree on a price for a defined scope. The vendor absorbs the risk of it taking longer. You trade some flexibility for predictability and a clear cap.
Where each makes sense
- Hourly: ongoing, open-ended, or genuinely exploratory work where scope cannot be pinned down.
- Fixed fee: a defined deliverable, an MVP, a foundation, a specific tool, where you want budget certainty.
The catch with fixed fee
A fixed fee only works if the scope is clear. Vague scope forces vendors to either pad the price heavily or fight you over change requests. So the prerequisite for a fair fixed price is a well-defined product.
This is part of why a product simulation is sold as a flat, scoped fee: the deliverable, a documented, runnable foundation, is concrete enough to price honestly. You know the number before anything starts, and you are not funding someone's learning curve by the hour.
When you can define it, fix the price. Start a project for a clear, flat-rate scope.
Frequently asked
Isn't hourly more fair since you only pay for work done?
It sounds fair, but it puts all the risk of inefficiency and unclear scope on you. With hourly, you pay for the time spent figuring out what to build, and you cannot predict the total.
When does hourly actually make sense?
For genuinely open-ended or exploratory work, or an ongoing partnership where scope shifts constantly. For a defined deliverable, a fixed fee protects you better.