Check In and Out at Work (CIAO) from 1 April 2027: What Changes

From 1 April 2027, presence on construction sites above 500,000 euro must be registered both on arrival and on departure – and Check-in-at-Work will no longer accept those registrations at all. The RSZ announced this on 30 July 2026. Here is what it actually says.

What has been decided

The Programmawet of 30 May 2026 (title 6, chapter 1, articles 124 to 131) introduces a duty to register presence IN and OUT for:

• works in immovable state, excluding cleaning activities, and
• the delivery of ready-mix concrete

It applies to places where the total value of the works is 500,000 euro excluding VAT or more. The service that handles it is Check in and out at work (CIAO), provided by the RSZ.¹

When it starts, and what stops

The obligation takes effect on 1 April 2027. The RSZ has been explicit that the date was pushed back deliberately, to guarantee a fully functional application and to give employers time to prepare.¹

The part that is easy to miss: from that same date it will no longer be possible to register presence for works in immovable state in Check-in-at-Work. This is not CIAW plus an extra field. For these sites, the registration moves to a different service.¹

What is actually different from CIAW

Thresholds for CIAW are 500,000 euro excluding VAT for works started after 29 February 2016; works started between 1 April 2014 and 29 February 2016 used 800,000 euro.²

Who this affects

The registration duty already sits with employers and contractors: they register their own employees, their subcontractors and their self-employed subcontractors, and workers may also register themselves.¹ Nothing in the new rules moves that responsibility. What changes is that for these sites you now need a departure record for every one of those people, every day.

If you are a main contractor, that is the bit worth thinking about now. Capturing an arrival is easy – people turn up in a group at the start of a shift. Capturing departures is harder, because people leave at different times, in ones and twos, often without passing a fixed point.

What to do between now and April 2027

1. Work out which of your sites cross 500,000 euro. The duty follows the site value, not your company size.
2. Check whether your current method can record an OUT at all. A badge scanned on arrival at a gate is not automatically a check-out mechanism.
3. Decide how departures get captured without someone standing at the exit – app, geofence, or a registration point people actually pass on the way out.
4. Confirm your works declarations are in order. Sites subject to registration must be declared in the Aangifte van werken, and the RSZ writes to the declared parties with reference CAWON.²
5. Do not wait until March 2027. The switchover is a fixed date, and it removes the option you are using today.

Where to watch for updates

The RSZ has said more information will follow on the Check in and out at work portal page. Detail on the practical registration flow is still being published, so treat the operational specifics as provisional and the dates and thresholds as settled.

Suivo already handles Check-in-at-Work registration for Belgian construction sites, including subcontractors and third parties. If you want to talk through what April 2027 means for your sites, get in touch.

Sources

1. RSZ/ONSS, Checkinatwork – alert of 30 July 2026, “Check in and out at work voor werken in onroerende staat vanaf 1 april 2027”.
2. RSZ/ONSS, Werken in onroerende staat – drempelbedragen.
Checked against the official sources on 30 July 2026. Verify against the RSZ pages before relying on this for a specific project.