The definitive 2026 sector-by-sector guide to Belgian CIAW thresholds, exemptions, and the chain-liability rules that decide who registers, who pays, and who walks away clean.
Belgian Check in at Work (CIAW) is not a single, uniform obligation. It is a layered framework where the answer to “do I need to register?” depends on your sector, the contract value, the number of subcontractors on site, and increasingly on whether your work requires entry-and-exit times rather than a single check-in. Get the threshold logic right and compliance is straightforward; get it wrong and a single site can trigger fines into six figures. This definitive 2026 guide walks through every sector the NSSO currently regulates under the Check in at Work framework, with the thresholds, the exceptions, and the practical implications for contractors, subcontractors, and posted workers. It is the article we send when a customer asks “do I need this at all?”
Quick Navigation
- The 30-second answer
- Construction: the original CIAW sector
- Cleaning: the first sector on full CIAO
- Meat processing: low threshold, high stakes
- Posted and foreign workers: the Limosa overlay
- Sector-by-sector quick reference
- Exemptions and edge cases
- What’s expected in 2027 and beyond
- Managing CIAW with technology
- Frequently Asked Questions
The 30-second answer
If your business operates in construction, cleaning, or meat processing in Belgium, you are very likely already in scope of CIAW. The fastest way to find out:
❌ Assuming “small projects” are exempt across the board
✅ Checking the sector-specific threshold against the actual contract value
❌ Treating subcontractor obligations as the main contractor’s problem
✅ Registering every worker, every day, on every site that crosses a threshold
For the official text, see the Belgian Social Security portal and the NSSO’s Check in at Work guidance. For day-to-day operational implications, the Suivo CIAW solution covers each sector explicitly.
| ⚠️ Important regulatory warning: CIAW thresholds apply per project and per subcontractor. A single project below the contract threshold but with two or more subcontractors automatically pulls every party into the registration regime, regardless of individual contract size. The Belgian Data Protection Authority also has views on how that worker data is then handled, minimise capture and retain only what is required. |
Construction: the original CIAW sector
Construction (works on immovable property) has been in scope of CIAW since the regime was introduced and remains the highest-volume sector by far.
The thresholds:
- Main contract over €500,000, every subcontractor, sub-subcontractor, and worker on the project must register, regardless of individual contract size.
- Subcontractor invoice over €5,000, that subcontractor and its workers must register.
- Two or more subcontractors on site, every party must register, regardless of contract size.
Chain liability is the defining feature of construction CIAW. The main contractor is responsible for ensuring every subcontractor, including the subcontractors’ subcontractors, has registered. The detailed construction industry overview on the Suivo site lays out how a typical compliant site is structured, with the confederation of construction publishing sector-level guidance that mirrors NSSO interpretation.
In practice, very few professional construction sites fall outside CIAW. The exceptions are small residential renovations with a single subcontractor and contract values well below €5,000, and even those rapidly cross threshold the moment a second trade arrives.
Cleaning: the first sector on full CIAO
The cleaning sector was the first to move from CIAW to the full Check in and Out at Work (CIAO) regime in 2025. The threshold is lower and the registration requirement is stricter:
- Cleaning contract value over €30,000 triggers the obligation.
- Every worker must register both entry and exit times, not just a daily check-in.
- Multi-site cleaning operations need to register per site, not per company.
This makes cleaning a particularly app-dependent sector. Manual paper logs do not capture entry and exit reliably across multiple sites, and the data flow has to land at the NSSO continuously, not at end-of-month. Tools that handle CIAO natively, rather than retrofitting CIAW with an “exit” button, are the only practical option. Facility managers running mixed contracts often pair the CIAO module with time tracking for unified payroll exports.
Meat processing: low threshold, high stakes
The meat-processing sector has the lowest threshold of any current CIAW industry:
- Meat contract value over €5,000 triggers the obligation.
- Applies to processing facilities, deboning, packaging operations, and ancillary services.
- Cold-chain and food-safety overlays add additional compliance layers.
The combination of a very low threshold and intensive shift work means most meat-processing operations are continuously in scope. The Belgian Social Security portal publishes sector-specific guidance, and we expect this sector to move to full CIAO entry-and-exit registration in the next regulatory cycle.
Posted and foreign workers: the Limosa overlay
Any non-Belgian worker working in Belgium for a foreign employer must first have a valid Limosa declaration. CIAW then sits on top: the worker must also be registered for each site where they perform in-scope work.
Practical sequence:
- File the Limosa declaration before the first day of work.
- Set up the worker in your CIAW system using their BIS number.
- Register each day on each site, the same as a Belgian worker.
Missing Limosa is the single most common reason an otherwise-compliant CIAW registration is rejected by the NSSO submission endpoint. For details on running a chain that includes posted workers, see the Suivo CIAW FAQ.
Sector-by-sector quick reference
| Sector | Threshold | Type of registration | Chain liability | Notes |
| Construction (main contract) | €500,000 | CIAW (check-in) | ✅ Full | Most common scenario; almost all sites in scope |
| Construction (subcontract) | €5,000 | CIAW | ✅ Full | Triggers regardless of main contract value |
| Construction (2+ subs on site) | Any value | CIAW | ✅ Full | The most-missed trigger |
| Cleaning | €30,000 | CIAO (check in and out) | ✅ | Active since 2025 |
| Meat processing | €5,000 | CIAW | ✅ | Likely to move to CIAO next |
| Posted / foreign workers | n/a, always | CIAW + Limosa | ✅ | Limosa must be filed first |
| Pure consultancy on site | n/a | ❌ Generally not | n/a | Confirm in writing if unsure |
Always check sector-specific guidance; the table summarises the most common interpretations as of 2026.
Exemptions and edge cases
❌ Maintenance work that doesn’t touch immovable property structure, usually exempt, but document it.
✅ Repair work that involves structural elements, in scope above the threshold.
❌ Pure office or administrative work performed off-site, exempt.
✅ Office work performed inside the construction site cabin, still exempt, but workers should not pass through active site zones without registering.
❌ Volunteer or unpaid work, generally exempt from CIAW, though other obligations may apply.
✅ Paid casual or temporary work, in scope the moment a worker is paid.
Genuine grey areas exist around restoration, infrastructure maintenance, and short-duration emergency interventions. The honest answer is that the NSSO interpretation is conservative, when in doubt, register. The downside of registering an exempt job is zero; the downside of not registering an in-scope job is administrative or criminal sanctions per offence, refer to the NSSO Check in at Work guidance for current amounts.
What’s expected in 2027 and beyond
- 2027 outlook: Belgium is expected to expand mandatory daily time registration to every employer. CIAW would then sit alongside a broader time-tracking obligation; sectors currently exempt from CIAW will still need a time-record system. Track the legal route via official channels rather than blog summaries.
- CIAO expansion: Construction and meat are the most cited candidates for entry-and-exit registration in the next regulatory cycle.
- Threshold indexation: Annual review of the fine amounts; expect upward adjustment in 2027.
- Sector tightening: Cold-chain logistics and waste handling are emerging discussion points in sector federations.
Managing CIAW with technology
Suivo, a Belgian IoT and compliance company with over 15 years of experience, builds CIAW and CIAO tooling designed to handle every Belgian sector under one platform. Their software helps you:
- Apply the right registration logic per sector automatically, CIAW for construction and meat, CIAO for cleaning, without manual configuration.
- Capture every worker via the Check in at Work app, site-pole hardware, or vehicle-tracker handshake.
- Verify Limosa status before issuing a CIAW account, removing the most common rejection cause for foreign-worker registrations.
- Sync hours directly into SD Worx, Partena, Acerta and your ERP via the time tracking module, ready for the 2027 mandate.
- Surface chain-liability gaps across subcontractors in real time, with dashboards tailored for the construction industry.
- Cover multi-sector operations (construction + transport + cleaning) without running parallel systems, including vehicle tracking and asset management.
- Provide NL/FR/EN local support from a Belgian team that has navigated every sector’s NSSO interpretation in practice.
Suivo’s IoT platform integrates seamlessly with existing payroll and ERP systems, helping companies like Hoogmartens, Cegelec, and Antwerpnatie stay compliant across sector boundaries without growing the compliance team.
“We operate in construction and cleaning, with a few meat-processing clients on the side. Having one platform that automatically applies the right registration logic per site removed a whole layer of admin we used to spend on every Monday morning.” – Compliance Manager, multi-sector facility services firm, Antwerp
Take Action Today
Don’t let an unclear threshold catch your business unprepared. Start by mapping every active project against the sector-specific threshold above, document the marginal cases, and plan now for the 2027 time-registration mandate that will pull non-CIAW sectors into a similar regime.
For more information about determining your CIAW obligations and choosing the right registration setup, contact Suivo at +32 3 375 70 30 or visit the Suivo CIAW solution page to see how their multi-sector platform helps Belgian businesses stay compliant across construction, cleaning, and meat processing. You can also explore the full product range, see current pricing, or book a demo.
Free Sector Compliance Guide
Want a printable reference for your compliance binder? Our free Sector Compliance Guide condenses this article into a single page per sector, plus the decision tree for marginal cases.
Inside, you’ll find:
- The 2026 thresholds, fines, and registration types for every regulated sector
- How Suivo helps with multi-sector compliance, Limosa, and chain liability
- Real-life lessons from Hoogmartens, Cegelec, Antwerpnatie, and Molenbergnatie
- Decision trees for construction, cleaning, and meat-processing edge cases
[Download the free Sector Compliance Guide →](https://www.suivo.com/contact/)
Frequently Asked Questions
Is CIAW mandatory for one-person self-employed contractors?
Often yes. The thresholds apply to the contract, not the headcount of the company performing it. A self-employed builder on a project above the threshold or alongside other subcontractors must register. See the Suivo CIAW FAQ for the most common one-person scenarios.
What if I work across construction and cleaning on the same day?
You apply both regimes. The construction site uses CIAW; the cleaning site uses CIAO entry-and-exit. A platform that handles both natively avoids the need for two separate apps. The Suivo CIAW solution supports both flows under one login.
My subcontractor refuses to register. What now?
Under chain liability, the main contractor is responsible regardless. Issue them a licence from your pool, escalate contractually, and document the refusal in writing. The construction industry overview includes model wording you can adapt.
When is CIAW *not* mandatory?
Pure consultancy with no physical site presence, volunteer work, and small private residential jobs below the threshold with a single subcontractor. Even then, document the assessment, inspectors prefer to see the reasoning rather than discover the gap themselves. For details and edge cases, see the Suivo CIAW FAQ.
Will the 2027 time-registration mandate replace CIAW?
No. CIAW will continue to serve its specific purpose for the regulated sectors, while the 2027 time-tracking mandate adds a broader daily working-hours obligation across every employer. The two will run in parallel.
