What is time and materials?
Time and materials, usually shortened to T&M, is a pricing model in which a client pays for the time actually worked at agreed rates, plus any materials or expenses. There is no fixed total. If the work takes longer, it costs more.
It is the default for consulting and freelance engagements in Belgium, normally priced on a day rate per profile. What it really settles is not the price but the ownership of scope risk.
Who carries the risk under time and materials?
The client. Under a fixed price the supplier absorbs the cost of work that takes longer than estimated, and prices a contingency into the quote for exactly that reason. Under T&M there is no contingency, because there is nothing to protect against: additional effort is simply additional invoice.
That makes T&M cheaper when the estimate holds and more expensive when it does not. The honest way to choose is by how well the work is understood. Well specified work with stable requirements suits a fixed price. Work where the specification will change as you learn suits T&M, because a fixed price on unknowable scope is either padded or renegotiated, and usually both.
What does time and materials require to work in practice?
Visibility and a ceiling. Without a cap or a stage gate, a T&M engagement has no natural point at which anyone reconsiders. A budget ceiling per phase, with an explicit decision to continue, keeps the flexibility while restoring a moment of choice.
Reporting has to match that. Hours by workstream, against what was expected, reviewed often enough that a drift shows up while it can still be acted on. T&M billing that arrives as a monthly total with no breakdown removes the only control the model has.
Does time and materials create a legal exposure in Belgium?
Not by itself, but it is the model most often found where the exposure exists. A T&M engagement priced by the day, with a consultant sitting in the client's team and taking daily direction, has the shape of the arrangement the law of 24 July 1987 prohibits when the client exercises part of the employer's authority.
The SPF Emploi guidance on making workers available to a user sets out the way through: welfare and safety instructions are always permitted, and any others require a written agreement stating precisely which instructions the client may give. The pricing model is not the problem. What the pricing model quietly allows is. This is the same boundary that governs staff augmentation, and it is worth settling before an engagement starts rather than during an inspection.
