CAO is summarized for: Collectieve Arbeids Overeenkomst (Collective labour agreement). A collective labor agreement is concluded by 1 or more employers, 1 or more employer organizations and 1 or more employee organizations (usually trade unions).

The agreements in a collective labor agreement may never conflict with the law. For example, with the Civil Code ('Burgerlijk Wetboek') and the Minimum Wage and Minimum Holiday Allowance Act. The collective labor agreement may therefore not contain a lower wage than the minimum wage or fewer vacation days than in the Civil Code. A law, for example the Civil Code, may also stipulate that statutory rules may be deviated from in a collective labor agreement.

This may sound weird, but the idea is that there are specific agreements for different sectors. For example working as a baker in a small bakery (during night/early morning) is different from working in a restaurant (in afternoon/early evening) and for a truck driving. Not all companies or sectors have an own CAO.

By law we and our clients need to threat our temporary employees the same as the employees on own contract. This means that we have to follow the CAO of our clients for those employees. If a client/sector doesn't have an CAO then we are obligated to follow the general NBBU CAO. This is special for temporary agencies.

Some things that often are agreed in this CAO's:
Normal working times
Salary scale
Overhours rates
‘other’ hours rates
Extra bonus