An uitzendovereenkomst is the tripartite employment arrangement defined in Article 7:690 of the Dutch Civil Code. The temporary staffing agency (uitzendbureau) is the formal employer, while the work is performed under the supervision and direction of a client company (inlener). Most agencies apply the national collective agreement CAO voor Uitzendkrachten (ABU or NBBU), which sets pay, phases, and allowances.
The CAO structures agency work into phases. Phase A covers the first 52 weeks and is highly flexible, with short contracts and a so-called uitzendbeding that allows the assignment to end when the client releases the worker. Phase B follows for up to three years with a maximum of six fixed-term contracts. Phase C grants an indefinite contract with the agency.
Agency workers are entitled to the inlenersbeloning, which equalises pay, allowances, and leave with employees in equivalent positions at the client. Reforms under the Wet toelating terbeschikkingstelling van arbeidskrachten (Wtta) introduce mandatory licensing for agencies from 2026.