Social bureau in Ghent, partner of Acerta
Social
secretariat
for employers.
One choice. Everything depends on it. Your social secretariat files the declarations the law requires of you. The choice of who manages it determines whether your personnel administration is correct, or whether you overpay or underpay for years without knowing.
The basics
euros maximum criminal fine per employee for intentionally incorrect NSSO declarations, for an employer who is a natural person (a company risks up to €720,000)
The NSSO audits systematically. An error in your DmfA declaration can lead to sanctions, recoveries and, in serious cases, criminal prosecution of the employer personally.
Legal obligation (NSSO Act)
No law requires you to join a social secretariat. Every employer with staff must however be in order with Dimona, payslips, the quarterly DmfA and payment of contributions, either directly or through a social secretariat.
What is a social secretariat?
A social secretariat is an officially accredited intermediary between you as an employer and the NSSO. Every time you pay someone, wages, NSSO contributions and withholding tax must be calculated and declared: wages and contributions every quarter via the DmfA declaration, withholding tax separately to the FPS Finance.
That sounds simple. In practice, your joint committee determines which minimum wages, year-end bonuses, indexations and additional benefits apply. There are 98 joint committees and 66 joint subcommittees in Belgium. Each has its own rules.
What a social secretariat does:
The market
The accredited social secretariats in Belgium
Business Centrum is the recognised partner of Acerta. We handle all communication and processing through this social secretariat.
| Secretariat | Profile | Strong for | Typical JC |
|---|---|---|---|
| Acerta | Broad audience, strong digital tools | SMEs and liberal professions | All sectors |
| Securex | HR consulting, international files | White-collar workers, international companies | JC 200 |
| SD Worx | Large enterprises, advanced software | Payroll at scale, complex files | All sectors |
| Liantis | Flemish, cooperative model | Self-employed and SMEs | JC 140, JC 124 |
| Group S | Non-profit and social profit | Care sector, education, non-profits | JC 330, JC 319 |
Business Centrum is the recognised partner of Acerta
You don't choose a secretariat, you choose Business Centrum. We select the most suitable secretariat for your situation, carry out the transfer and remain your fixed point of contact.
How it works
What does Business Centrum do as a social bureau?
Without an intermediary, you communicate directly with your secretariat's call centre: a different employee every time, explaining everything again every time. With Business Centrum, you have a fixed person who knows your business.
You - the employer
Y
- ›Submits hours worked
- ›Reports new employees
- ›Asks questions
- ›Focuses on your business
Business Centrum
BC
- ›Knows your file completely
- ›Translates your situation into HR rules
- ›Communicates with the secretariat
- ›Proactively flags errors or opportunities
- ›Is reachable when it matters
Social secretariat
SS
- ›Technically processes the declarations
- ›Submits DmfA to the NSSO
- ›Generates payslips
- ›Works in the background
We are your single point of contact.
The risks
What goes wrong without guidance?
Many employers think HR is "just some paperwork". What they don't know: the NSSO can claim contributions up to 3 years back, up to 10 years in case of fraud. A mistake today will cost you in five years the difference on all those wages, plus fines, plus interest.
Cost escalation without guidance
Concrete errors and their cost
Wrong joint committee
Up to 5 years backRepayment of wage difference
Example: JC 302 instead of JC 200 = wrong pay scales over 5 years
Late DmfA
Min. €495.79/quarterFlat-rate charge payable to the NSSO
Example: Forgotten quarterly declaration for 3 employees
Incorrect NSSO calculation
7% interest per yearRecovery + interest
Example: Wrong NSSO rate for 2 years
Intentionally incorrect NSSO declaration
Up to €70,000 per employee (company: up to €720,000)Criminal prosecution possible
Example: Wages under-declared to save on contributions
Warning: errors are retroactive
The NSSO can claim contributions up to 3 years back, up to 10 years in case of fraud. An incorrect joint committee number today means you will have to pay the difference for all wages of the past 5 years, including interest and fines.
Years of retroactive effect in an NSSO audit
That is how far back the NSSO can claim contributions. In case of fraud or false declarations, 10 years.
In practice
Monday 08:00. A new employee starts tomorrow.
You send us a message. We do the rest.
Send an email: "Jan Pieters starts tomorrow as a white-collar worker, gross €2,800."
Checks the joint committee, calculates the correct pay scale, submits the DIMONA declaration via the NSSO portal.
Drafts the employment contract in line with the JC, sends it for signature. Saves the file.
Processes the first payslip, submits all declarations, provides you with an overview.
Frequently asked questions
Employer questions about a social secretariat
Don't see your question? Get in touch with us.
Additional services
Read next
- Choose a social secretariat: seven criteria for SMEs
- Social bureau in Belgium: what it is, what it does for your SME and how it differs from a social secretariat
- Acerta or Business Centrum: the same social secretariat, two ways of working
- The largest social secretariats in Belgium in 2026: the official list and how big each one is
- Acerta vs SD Worx, Securex, Liantis or Partena: the differences pair by pair, with source and date
- Switching social secretariat in Belgium: when and how
- Social secretariat cost in Belgium: prices and pitfalls
Sources
Every amount and deadline on this page was checked against these official sources, last consulted on .
- FOD WASO, Oprichting en samenstelling van de paritaire comites
- Justel, wet 29 juni 1981 algemene beginselen sociale zekerheid werknemers, art. 31quater par. 3; RSZ 2026/3, mandaat
- RSZ, administratieve instructies 2026/3, de gevolgen van een nalatigheid (art. 28 wet 27 juni 1969)
- RSZ, administratieve instructies 2026/3, DmfA algemeen
- RSZ, Administratieve instructies, De verjaring
- RSZ, Administratieve instructies, Sancties DmfA
- RSZ, Jaarverslag 2025, Adviseren en toezicht houden
- Sociaal Strafwetboek, art. 234 (Justel); FOD WASO, Wijzigingen aan het Sociaal Strafwetboek vanaf 1 september 2026
Ready to sort out your personnel administration once and for all?
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