Every client asking for a quote eventually asks why one agency offers a fixed price and another wants to bill hourly for the same-sounding project. Both are legitimate; they just answer a different question about who absorbs the risk when the scope inevitably shifts.
Fixed price: predictability, in exchange for rigidity
A fixed price only works when the scope is genuinely well-defined upfront — a clear spec, agreed features, agreed pages. In exchange for budget certainty, you give up flexibility: a mid-project change means a formal change order, usually with its own cost and timeline impact. This suits well-scoped projects with a client who knows exactly what they want.
Time & materials: flexibility, in exchange for an open number
T&M billing charges for actual hours worked, which means the project can evolve as you learn — a common and healthy pattern in software, where the third sprint often reveals something the first sprint's spec didn't anticipate. The tradeoff is an open-ended total cost, which requires real trust and active budget management on both sides, not a "set it and forget it" contract.
The version that actually protects both sides
Many well-run projects use a hybrid: a fixed price for a clearly-scoped first phase — discovery, design, core build — followed by time & materials for ongoing iteration once real usage data starts shaping priorities. This gives the client budget certainty where it's possible to have it, and flexibility where rigid certainty would just produce the wrong thing built on schedule.
The question that decides which one you should choose
How confident are you, honestly, that the spec won't change? If a competitor's launch or your own user feedback is likely to reshape priorities mid-project, T&M or a phased hybrid will serve you better than a fixed price that locks in assumptions you don't yet trust.
Where to start
- Write the spec as precisely as you can before asking for a fixed-price quote — vague specs produce fixed prices with padding built in to cover the agency's risk.
- If you expect the scope to evolve, ask for T&M or a phased hybrid instead of forcing a fixed price onto a moving target.
- For T&M, ask for weekly time reporting, not just a monthly invoice — visibility is what makes the model work.
- Whichever model you pick, agree in writing on how scope changes get handled before the project starts, not during the first one.
