Time-and-materials billing is the easier answer for almost anyone offering technical services. It shifts all the estimation risk onto the client, and it means an agency never has to say no to scope creep — every extra hour is more revenue. It's also, in our experience, the thing that erodes trust fastest.
What fixed-scope actually forces us to do
Quoting a number before writing any code means we have to do the scoping work up front, out loud, with the client in the room. That conversation surfaces the assumptions that would otherwise turn into disputes three months in.
- We document what's in scope and, just as importantly, what isn't.
- We flag ambiguous requirements before they become expensive surprises.
- We hold the number, or explain in writing exactly why it changed.
A fixed quote is a bet that we understand the problem well enough to be accountable for it. If we're not confident enough to make that bet, that's information the client needs too.
Where it doesn't fit
Open-ended discovery work, or a project where the client genuinely doesn't know what they want yet, isn't a good fit for fixed-scope pricing — and we say so. In those cases we'll quote a short, capped time-and-materials phase specifically to get to a scope we can then fix a price against.
The trade-off we're making
Fixed-scope pricing means we sometimes eat the cost of our own estimation mistakes. We've made peace with that, because the alternative is a pricing model that quietly rewards vagueness.