Checkinatwork (CIAW): what do you have to register?
Checkinatwork is the online service of the NSSO (RSZ/ONSS) through which employers and contractors register who is present on a construction site. Here you can read who has to register, when, and what changes.
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Who has to register?
Employers and contractors register the attendance of their own employees, of their subcontractors and of self-employed subcontractors. Employees and self-employed subcontractors can also register themselves.
From which amount?
The obligation applies to construction sites where the total amount is equal to or higher than 500,000 euros (excluding VAT).
In which sectors?
- Works on immovable property (construction work), excluding cleaning and certain activities in agriculture, horticulture and forestry.
- The delivery of ready-mixed concrete.
- Activities in the meat sector.
When do you register?
Every day, before the person carrying out the works starts work.
What changes with check-in and check-out?
For works on immovable property, registering attendance on arrival and on departure becomes mandatory. That is laid down in the programme law of 30 May 2026 (title 6, chapter 1, art. 124 to 131). That obligation starts on 1 April 2027. From then on you can no longer register attendance for works on immovable property in Checkinatwork.
How do you register?
Through the NSSO’s online service Checkinatwork, or with an app or system that forwards the registration automatically. See which apps do that in our comparison of Checkinatwork apps.