CIAW, CIAO, fines, automation, and payroll integration for local and international contractors
Belgium has some of the strictest time and attendance registration requirements in Europe, particularly in construction. Between CIAW presence registration, CIAO for cleaning subcontractors on site, working-time legislation, and CLA-specific overtime rules, getting it right is both legally required and operationally critical.
This guide is written for construction companies operating in Belgium, whether headquartered here or working on Belgian sites as international contractors.
Take the next step and explore Suivo’s Time Tracking solution.
Guide Navigation
- The Belgian Registration Landscape
- Who Must Register?
- For International Contractors
- Registration Methods
- Choosing Software for Belgian Construction
- Frequently Asked Questions
The Belgian Registration Landscape
CIAW (Check in at Work)
Mandatory electronic presence registration for construction sites. Every worker must be registered daily before starting work. Data is transmitted to the NSSO (RSZ) in real time.
- No subcontractor: projects > €500,000 excl. VAT
- 1 subcontractor: projects > €5,000 excl. VAT
- 2+ subcontractors: always mandatory, no threshold
Fines: €600–€6,000 per worker per day for missing or incorrect registrations.
CIAO (Check in and Out at Work)
Since April 2024, cleaning activities on construction sites or buildings fall under CIAO, requiring both check-in and check-out. No threshold amount. If you subcontract cleaning on your site, those workers need CIAO registration too.
Working-Time Rules
Belgian labour law requires employers to maintain verifiable working-time records. Construction-specific CLAs add overtime premiums, shift allowances, and travel-time compensation rules that must be calculated accurately for payroll.
2027 Expansion
Mandatory digital time registration will extend beyond current CIAW/CIAO sectors by 2027. Construction companies that digitise now benefit from 12–18 months of operational improvement before the expanded mandate takes effect.
Who Must Register?
Everyone physically on a qualifying site:
- Own employees of the main contractor
- Subcontractor workers at all chain levels
- Temporary agency workers
- Self-employed contractors and freelancers
- Foreign workers (with valid Limosa L1 declaration)
- Trainees and interns
For International Contractors
If you send workers to Belgian construction sites, you need:
- Limosa declaration, filed before each worker enters Belgium. Produces an L1 document with a unique Limosa number
- CIAW registration, daily check-in using the Limosa number instead of a Belgian INSZ number
- Working-time compliance, Belgian rules apply while working on Belgian territory, regardless of your home country
❌ Common mistake: Many international contractors believe Limosa filing makes them compliant. It doesn’t. Limosa is pre-registration. CIAW is the daily check-in. Both are required.
Registration Methods
| Method | How It Works | Key Requirement |
| Mobile app | Worker taps ‘Clock in’. GPS verifies location. | WiFi/mobile data required for every registration |
| Site terminal | RFID badge scan at site entrance. | Terminal needs power + connectivity |
| Vehicle hardware | RFID badge + geofence. Automatic when vehicle enters site. | Hardware installed; geofence configured |
Suivo requires WiFi or mobile data for every time registration, by design, to ensure data integrity and prevent manipulation.
Choosing Software for Belgian Construction
- CIAW/NSSO integration, automatic transmission, not manual upload
- GPS verification, confirms correct site location
- Construction CLA rules, automatic overtime and premium calculations
- Payroll integration, SD Worx, Partena, Acerta via API
- Subcontractor + Limosa support, all worker types in one system
- Local NL/FR/EN support, critical for compliance questions
For a comparison, see our best time registration tools guide. Explore construction solutions.
Frequently Asked Questions
Does Suivo work for international contractors on Belgian sites?
Yes. Workers register with their Limosa number. The platform supports NL/FR/EN. Suivo handles both Limosa tracking and CIAW registration in one system.
Is time registration the same as CIAW?
No. CIAW is presence registration (who is on site). Time registration tracks actual working hours for payroll. Suivo combines both in one clock-in action.
Operating on Belgian construction sites?
One platform for CIAW, time tracking, and payroll, for local and international teams.
