A plain comparison of fixed-price and time-and-material contracts for software projects, when each works, the risks for buyers, and the hybrid model most product teams end up using.
A plain comparison of fixed-price and time-and-material contracts for software projects, when each works, the risks for buyers, and the hybrid model most…
Choose **fixed price** when the scope is small, clear and unlikely to change – a website, a migration, a well-defined feature. Choose **time and material (T&M)** when you're building a new product and expect to learn and change direction. For most new apps the best fit is a **hybrid**: a fixed-price discovery, then T&M (or fixed-price milestones) for the build.
• You can describe every screen and rule today. • The deadline or budget is non-negotiable (a grant, an event, a board approval). • The work is a known type: marketing site, rebuild of an existing app, API integration. Ask for a written list of assumptions and exclusions. An honest fixed quote includes a buffer – that's the price of certainty, not a trick.
• You're building something new and will learn from users. • You want to change priorities every 1–2 weeks. • You have a product owner who can make decisions quickly. Protect yourself with a **monthly cap**, a **weekly demo**, a shared backlog and timesheets you can see.
1. **Fixed-price discovery (1–2 weeks):** flows, prototype, architecture, estimate. 2. **Build in fixed-price milestones or capped T&M sprints:** you see working software every 2–4 weeks. 3. **Retainer after launch** for fixes and improvements. This gives you a firm number for the first decision and flexibility once real feedback arrives. Further reading: [How to Choose a Software Development Company in 2026: A Buyer's Checklist](/blog/how-to-choose-a-software-development-company) and [Custom Software Development Cost UK 2026](/blog/custom-software-development-cost-in-the-uk-2026-pricing-gui
We offer fixed-price and time-and-material engagements and will tell you which fits your scope. [Get in touch](/contact) or read [what an MVP really costs](/blog/mvp-development-cost).