Fixed Fee, Time and Materials, or Capped: Choosing a Pricing Model

Fixed fee: certainty you have to earn first

Fixed fee works when scope is genuinely known: repeat engagement types, well-understood drivers, and a client whose environment you have seen. Under those conditions it is the most profitable model you can run, because your delivery efficiency accrues to you.

It fails when it is used as a sales concession on scope that was never resolved. Wellingtone's State of Project Management 2024 found only 34% of organisations mostly or always complete projects on budget — fixed fee over unresolved scope simply moves that risk onto your balance sheet.

• Requires: closed scope, stated assumptions, bounded revisions, working change control.
• Protect it with: named dependencies, deemed acceptance, and a phase structure you can defer.

Time and materials: honest, and harder to sell

T&M is the correct model when the work is genuinely exploratory, when the client's environment is unknown, or when priorities will be reset during the engagement.

Its weakness is buyer confidence, not fairness. Clients fear open-ended spend, so the burden shifts to governance: transparent burn reporting, a named decision-maker, and a rhythm of showing what the money bought.

• Requires: rate card, estimated envelope, and a stated reporting cadence.
• Protect the relationship with: weekly burn visibility and a re-planning trigger.

Capped time and materials: the common compromise

A cap gives the client a ceiling and gives you honest billing beneath it. It is a reasonable middle ground, with one caveat: you carry all the downside and share none of the upside, so the cap needs the same discipline as a fixed fee.

Treat the cap as a fixed fee for risk purposes. Same assumptions, same exclusions, same change control, same review of what happens when the cap is approached rather than after it is reached.

Retainer: for capacity, not for deliverables

Retainers work when the client is buying access to capability over time — advisory, ongoing optimisation, managed support. They fail when they are used to fund a defined project without defining it.

State what the retainer includes as a quantity of capacity, what carries over, and what is explicitly a project requiring its own SOW.

Milestone-based fixed fee: the practical hybrid

Most large engagements are better priced in phases than in one number. Fix the phase you understand, price the later phases indicatively, and re-estimate each one at its gate using what the previous phase taught you.

This is often the honest answer to a client who needs a fixed price for a project that cannot yet support one: a fixed discovery phase, followed by a fixed build priced on what discovery found.

Make the model visible in the document

Whatever you choose, the SOW should say why. A sentence explaining that the fee is fixed on the basis of the stated assumptions, or that the engagement is T&M because scope will be set during phase one, prevents the model being misremembered later.

That sentence costs nothing and is quoted back approvingly more often than any other line in a services contract.