Contract staffing is cheaper as long as you need someone for less than roughly four to six months. Past that point the math tips toward permanent placement, and from there the gap widens every month. For a senior engineer, a year in, you’re looking at a difference of forty to fifty thousand euros.
That’s the arithmetic. But the choice is rarely about money alone, because the two models differ most in who carries the risk and where the knowledge ends up.
What’s the actual difference?
With permanent placement, an agency finds a candidate who then joins your payroll directly. You pay a one-time fee, usually a percentage of gross annual salary, and only if the hire happens. After that the relationship is done. The engineer is your employee, on your terms, with your career path.
With contract staffing, the engineer stays employed by a staffing firm and works for you on an hourly rate. You pay for as long as the assignment runs. You can usually stop on short notice, you carry no employer risk, and you also don’t have an employee.
Contract-to-hire sits in between: you start with contract staffing and take the engineer onto your payroll later, often after twelve months, against a conversion fee of fifteen to twenty-five thousand euros. You’re buying time to evaluate, and paying for it.
Where’s the break-even point?
Run it with a senior backend engineer.
Through contract staffing you pay an hourly rate. For senior IT level in the Netherlands that runs roughly 75 to 175 euros, with most landing around 110. At about 1,550 billable hours a year, so after holidays, public days, and sick leave, that comes to around 170,000 euros annually. No fee, no employer charges, no sick pay obligation.
Through permanent placement you pay the fee once and then the salary. At 95,000 euros gross with a 19 percent fee, that’s 18,050 euros one time, plus roughly 123,500 euros a year in salary and employer charges combined.
So the difference is about 47,000 euros a year in favor of hiring directly, close to 4,000 euros a month. Which means that one-time fee of 18,050 euros pays for itself in just under five months. Shorter assignment, contract staffing wins. Longer, and you pay that difference every month.
Two caveats that can shift the outcome. Contract staffing includes insurance you never see itemized: if the engineer drops out, that’s the firm’s problem, not yours. And your employer charges depend on your pension scheme and benefits, so the 30 percent in this example is a midpoint, not a law.
So when is contract staffing the right call?
In four situations it’s simply the better answer, even at a higher hourly rate.
A finite project. A migration, a certification track, a peak that’s over in eight months. You’re buying capacity, not a colleague.
A gap that has to close now. A departure you didn’t see coming, with a team that’s blocked today. A good staffing firm has someone available; a senior search takes six to twelve weeks.
A scarce specialization you don’t need permanently. A security architect for three months is a smart contract and a poor permanent hire.
Genuine uncertainty about the role. If you don’t know whether this function still exists in a year, contract staffing buys you flexibility. That’s a legitimate reason to pay more.
What does the WTTA mean for you as a client?
This is the part still getting skipped in 2026, and it hits you directly as the hiring company.
The Dutch Wet toelating terbeschikkingstelling van arbeidskrachten, the WTTA, takes effect on 1 January 2027, with enforcement from 1 January 2028. From then on, any party supplying labor needs an admission, even for a single contractor. That admission requires a certificate of conduct, demonstrably correct pay and remittance, and a deposit of 100,000 euros. Starters can get provisional admission at 50,000 euros, topped up to the full amount later.
The part that matters for you: the obligation cuts both ways. Hiring from a party without admission becomes a finable offense for the client, not just the supplier. The admissions register will be public, so from 2027 onward “are you in the register” belongs in your standard procurement questions. That applies to foreign suppliers placing people here as well.
On top of that, contract staffing has simply gotten more expensive in 2026. The StiPP pension contribution rose to 23.4 percent in total as of 1 January 2026, of which 15.9 percent is the employer’s share, and the equal-pay obligation now covers the full benefits package. Those costs sit inside the hourly rate you pay.
What Renforza does, and deliberately doesn’t
Renforza does permanent placement. The engineer joins your payroll, we invoice once on a successful placement, and the knowledge stays in your house.
If you do need contract staffing or contract-to-hire, we arrange it through a certified payroll partner, never on our own books. That’s a deliberate choice, not a temporary one: the deposit, the pension remittance, the sick pay obligation, and the working capital all belong with a party built for it. That partner earns a few euros an hour for it, and that’s a fair price for work we wouldn’t do better.
Not much changes for you: you keep a single point of contact, and we stay accountable for the match. What you gain is that we have no interest in a long runtime. A staffing firm earns on every month someone stays seated. We earn once, which means we only earn on a match that holds.
How do you decide?
Start with the duration and the certainty of the role, not the rate. If you know this function still exists in two years, permanent placement is almost always cheaper and you’re building your own team along the way. If the role is temporary, uncertain, or urgent, contract staffing buys you something real: flexibility and speed.
And ask every staffing quote how the hourly rate breaks down and, from 2027, about admission. Ask every placement quote about the fee base and the guarantee period. That’s all worked through in what a recruitment agency costs.
Not sure which way a specific role should go? Take a look at our page for employers and book an intake. We qualify the search with MATCHED and we’ll tell you straight when contract staffing is the better answer in your case.
More from this cluster: what a recruitment agency costs, and hiring an agency or recruiting in house.
