The verdict in three sentences
The choice between fixed price and time and materials decides who bears the risk of scope creep on your web app. Fixed price locks scope and shifts risk to the vendor, but costs more and suits stable needs poorly; time and materials (day rate 450-700 EUR net) offers flexibility but demands active scope management. In 2026 in Dublin, the sweet spot is often a fixed-price discovery followed by managed T&M in 2-week sprints.
Fixed price vs T&M: the comparison
Both models fit different situations. Here are 2026 orders of magnitude for a 40,000-120,000 EUR net web app.
| Criterion | Fixed price | Time and materials |
|---|---|---|
| Scope | Locked in contract | Evolving per sprint |
| Creep risk | Vendor | Client |
| Price (risk margin) | +15 to 25 % | day rate 450-700 EUR net |
| Change flexibility | Low (change orders) | High |
| Client steering required | Low | Active (backlog) |
| Ideal for | Clear, stable need | Evolving need, product |
Fixed price reassures on a clear, stable need, but each change becomes a change order, often billed at a premium. T&M suits products that will evolve, provided a client-side product owner can prioritise the backlog.
Sprints, budget and warranty
Whatever the model, an agile methodology in 2-week sprints structures delivery and limits nasty surprises.
| Element | Fixed price | Time and materials |
|---|---|---|
| Typical project duration | 4 - 7 months | 4 - 8 months |
| Delivery cadence | Contractual milestones | End of each sprint |
| Indicative budget (EUR net) | 45,000 - 120,000 | 40,000 - 110,000 |
| Post-delivery warranty | 3 - 6 months included | to negotiate (maintenance) |
| Cost visibility | Full at signature | Per consumed sprint |
Warranty is a contractual point to check: in fixed price it is usually included (3 to 6 months of bug fixing). In T&M it is negotiated, often via a separate maintenance contract.
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Mini case study
Mark, director of a logistics SME in Dublin, wants a fleet-tracking web app. His need is still fuzzy: he hesitates between fixed price and T&M. In fixed price, the vendor quotes 95,000 EUR (net) (with about 20 % risk margin) for locked scope. In T&M, he estimates 130 days at 560 EUR net, i.e. 72,800 EUR (net), but with overrun risk. Mark chooses a fixed-price discovery at 8,000 EUR (specs + mockups), then managed T&M in sprints with an 85,000 EUR cap. Result: he saves about 10,000 EUR versus pure fixed price, keeps the flexibility to adjust scope, and secures his budget with a contractual cap.
FAQ
Is fixed price more expensive than T&M? Often yes: the vendor builds in a 15 to 25 % risk margin to cover the uncertainty of locked scope. T&M is cheaper if you manage scope well.
When should I choose T&M? When the need is evolving or you are building a product meant to change. T&M requires a client-side product owner to prioritise the backlog.
How do I secure a T&M project? Set a budget cap, work in 2-week sprints with delivery at each sprint end, and track consumed budget. You keep control at every step.
What warranty should I expect? In fixed price, budget 3 to 6 months of included bug fixing. In T&M, warranty is negotiated via a separate maintenance contract.
Is there a hybrid model? Yes: a fixed-price discovery (specs + mockups, 5,000-10,000 EUR) followed by capped managed T&M combines visibility and flexibility. It is often the best compromise in 2026.
Let's scope your project. Tell us whether your need is locked or evolving, your budget (40,000-120,000 EUR net) and target timeline: we recommend fixed price, T&M or a capped hybrid. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
