Since 1 May 2025, the transition period without sanctions for Check In and Out at Work (CIaO) has ended. NSSO inspectors have since been carrying out actual inspections, and a confirmed breach now results in a fine — no longer just a warning. Companies that prepare well avoid most unpleasant surprises.
What exactly does the NSSO check?
During an inspection on site, or afterwards via the NSSO database, it is checked whether every employee present was correctly checked in and out beforehand, and whether that registration matches the underlying Dimona declaration (own staff), Limosa notification (foreign workers), and the Declaration of Works (the contractor-subcontractor-site relationship). If one of these links is missing or incorrect, the system generates an error code — and that error code is exactly what an inspector also sees.
What fines do you risk?
The sanctions are laid down in the Social Criminal Code. For a breach of the CIaO registration obligation, this is usually a level 3 sanction:
- An administrative fine of €800 to €8,000, or
- A criminal fine of €1,600 to €16,000
- These amounts are multiplied per employee involved — with 5 incorrectly registered employees at a single location, a single inspection can already quickly cost €15,000 to €20,000.
These are figures from the official NSSO documentation and the Social Criminal Code, not an estimate by CIAO Assist. For a concrete assessment of your situation, we recommend consulting a social secretariat or a lawyer — this is not legal advice.
How do you prepare in practice?
- Check regularly — not just before an inspection — whether error codes have accumulated on your registrations.
- Resolve an incorrect or missing Dimona, Limosa, or Declaration of Works link as quickly as possible at the source, not afterwards.
- Keep track of which action has already been taken for which error code, so you can demonstrate this during an inspection.
- Involve your subcontractors: their registrations and declarations also help determine your own error codes.
- Request a clear overview of your current situation — before an inspection, not after.
What if error codes are already present now?
An error code is not a fine in itself, but a signal. As long as you know about it and follow up, you can still correct the underlying cause before an inspector finds it. Our error code guide explains, per code, the possible cause and the recommended action.
Do you know what's going on at your company?
CIAO Assist reads your registrations via the official NSSO connection and shows you, in plain language, which error codes are present, for whom, and since when. Start a free CIAO Check to find out today — no obligation, no subscription.