They sound similar, but they serve different purposes, follow different rules, and cover different data. Here is why you need to understand both.
If you manage a construction site in Belgium, you have probably heard the terms CIAW and time registration used interchangeably. Site managers, HR officers, and even payroll providers sometimes treat them as the same thing. They are not.
CIAW (Check in at Work) registers attendance, who was present on a construction site on a given day. Time registration records working hours, when someone started, when they stopped, and how long they worked. Confusing the two leads to compliance gaps, payroll errors, and missed operational insights. This article clarifies the difference between CIAW and time registration in construction so you know exactly what each system does, when you need them, and why most construction companies need both.
Why the Confusion Matters
The confusion between CIAW and time registration is not academic, it has real consequences. A site manager who believes CIAW covers time registration may discover during an NSSO inspection that while attendance records are in order, there is no compliant system for recording actual working hours. Conversely, a company with excellent time tracking may still face fines if workers are not registered in the CIAW system before starting work.
Understanding the difference is the first step towards a compliant, efficient, and future-proof workforce management setup on your construction sites.
What Is CIAW (Check in at Work)?
CIAW (Check in at Work), is Belgium’s mandatory electronic attendance registration system for construction sites. It was introduced by the Belgian government to combat social fraud in the construction sector and is enforced by the NSSO (RSZ/Rijksdienst voor Sociale Zekerheid).
Who Must Register?
CIAW is mandatory on construction sites where the total project value exceeds €500,000 (excl. VAT). Every person on site must be registered: own employees, subcontractor workers, temporary workers, and self-employed individuals. Registration must happen before the worker starts their day on site.
The obligation applies to construction, cleaning, and certain industrial activities. The main contractor is ultimately responsible for ensuring all parties in the chain are registered, this is the Belgian chain liability principle.
Penalties for Non-Compliance
Fines for missing CIAW registrations can reach up to €800 per violation per worker (after multiplication by the social surcharge). In severe cases, site access can be restricted and criminal proceedings initiated. During an NSSO inspection, every person on site must appear in the system, no exceptions.
What Is Time Registration?
Time registration is the recording of actual working hours, start times, end times, break durations, overtime, and total hours worked per day or per project. While CIAW answers the question “Was this person on site?”, time registration answers “How long did they work and on what?”
What Does Time Registration Capture?
| Data Point | Example |
| Clock-in time | 07:02 |
| Clock-out time | 16:31 |
| Break duration | 30 min (automatic deduction or manual) |
| Total hours worked | 9h 29min → 9h (after break deduction) |
| Project or cost centre | Site: Brussels Ring Road, Phase 2 |
| Overtime | 1h 29min flagged for premium rate |
| Absence type (if applicable) | Sick leave, public holiday, compensation day |
This data feeds directly into payroll processing, project costing, and resource planning, areas that CIAW does not touch.
The 2027 Mandate
From January 2027, all Belgian employers will be required to have an objective, reliable, and accessible system for recording daily working hours. Construction already has sector-specific obligations through CIAW, but the 2027 mandate goes further: it requires full time registration, not just attendance confirmation. Companies that only rely on CIAW will need to add time registration capabilities.
CIAW vs Time Registration: Side-by-Side Comparison
This table summarises the key differences:
| Aspect | CIAW (Check in at Work) | Time Registration |
| Purpose | Prove attendance on a construction site | Record actual working hours |
| What it records | Presence (yes/no per day) | Start time, end time, breaks, overtime, project |
| Legal basis | Belgian social security law (NSSO) | EU Working Time Directive + 2027 Belgian mandate |
| Who must comply | Construction sites >€500K + cleaning + industrial | All Belgian employers (from 2027) |
| Registration moment | Before work begins (daily) | At clock-in AND clock-out |
| Data output | Attendance confirmation to NSSO | Payroll export, project hours, overtime reports |
| Penalties | Up to €800/worker/violation | Pending, expected under 2027 legislation |
| Payroll integration | ❌ No, attendance only | ✅ Yes, direct export to SD Worx, Partena, Acerta |
| Project costing | ❌ No | ✅ Yes, hours per project/cost centre |
| Covers subcontractors | ✅ Yes, chain liability | Depends on agreement and system setup |
Why You Need Both
CIAW and time registration serve different purposes, and neither replaces the other:
CIAW without time registration means you can prove someone was on site, but you cannot calculate their pay, track overtime, or cost hours to a project. Payroll teams still rely on paper timesheets or manual input, with all the errors that come with it.
Time registration without CIAW means you have accurate working hours but no compliant attendance registration for the NSSO. You risk fines during inspections even if your payroll is perfect.
Both together give you full compliance (attendance confirmed for NSSO) plus full operational value (accurate hours for payroll, project costing, and resource planning).
How Suivo Covers Both in One Platform
Suivo’s workforce management platform handles CIAW registration and time registration from a single system. When a worker clocks in, via mobile app, vehicle badge, or site pole, the system simultaneously:
1. Sends the CIAW attendance registration to the NSSO (automatic, compliant, before work starts).
2. Starts the time registration clock (recording hours, project allocation, breaks).
3. Exports hours directly to your payroll provider, SD Worx, Partena, Acerta, or your ERP system (SAP, Dynamics, Odoo, KPD).
No double entry. No separate systems. One registration action covers both compliance and operational needs.
“Before Suivo, we had one system for CIAW and a separate Excel for hours. Now everything happens in one flow, our site managers save at least an hour per day.”, HR Manager, Belgian construction company (Suivo customer)
Frequently Asked Questions
What is the main difference between CIAW and time registration?
CIAW (Check in at Work) registers attendance, confirming a worker was present on a construction site on a given day. Time registration records working hours, start time, end time, breaks, and overtime. CIAW is a Belgian legal obligation enforced by the NSSO; time registration serves payroll, project costing, and resource management.
Do I need both CIAW and time registration on my construction site?
Yes, in most cases. CIAW is legally required on sites above €500,000 in value. Time registration is needed for accurate payroll processing and will become mandatory for all Belgian employers from 2027. Using both ensures full compliance and operational efficiency.
Can CIAW data be used for payroll?
No. CIAW only confirms presence (yes/no per day). It does not record start times, end times, breaks, or overtime, all of which are required for payroll calculation. You need a separate time registration system for payroll integration.
Can one system handle both CIAW and time registration?
Yes. Platforms like Suivo combine CIAW registration and time tracking in a single action. When a worker clocks in, the system sends the CIAW confirmation to the NSSO and simultaneously starts recording working hours for payroll and project costing.
What happens in 2027 if I only have CIAW?
From January 2027, all Belgian employers must have a system for recording daily working hours, not just attendance. If you only have CIAW, you will need to add time registration capabilities to comply with the new mandate. Companies that implement both now avoid rushed upgrades later.
Take the Next Step
Stop managing attendance and working hours in separate systems. Book your free expert session and see how Suivo handles CIAW and time registration from a single platform, compliant, connected, and ready for 2027.
