Acerta, SD Worx, Securex, Liantis and Partena are recognised social secretariats and file the same statutory returns, under the supervision of the NSSO. They differ in scale, region, tools, pricing model and the other services the group provides. SD Worx cites 92,000 Belgian payroll clients, Acerta more than 70,000 companies.
What do Acerta, SD Worx, Securex, Liantis and Partena have in common?
All five are on the official list of recognised social secretariats, dated 20 June 2025 and published in the Belgian Official Gazette on 15 July 2025. That list counts 25 recognised secretariats with an active head office. Each has its own recognition number, which you will find on your payslip and on their documents.
The statutory task is the same for all five:
- the Dimona at every start and end of employment;
- the payroll calculation and the quarterly DmfA;
- collecting the NSSO contributions and the payroll tax, and paying them on to the authorities;
- the social documents, such as the tax form and the holiday certificate.
The NSSO inspection monitors the quality of every secretariat with a barometer covering 6 control areas. In 2025, 83% of employers were affiliated with a recognised secretariat. An error in a return remains your responsibility as the employer, whichever secretariat you use. What the recognition involves and what to look for when choosing is covered in which social secretariat to choose.
So the difference does not lie in what the law requires. It lies in the way of working: how large the secretariat is, where it has offices, what software you and your employees get, how it builds its price and which services the group offers alongside the social secretariat.
Acerta vs SD Worx, Securex, Liantis and Partena side by side
The table puts the facts side by side as the official list and the secretariats themselves publish them. The head office comes from the official list, the other columns from their own websites.
| Secretariat (recognition number) | Head office according to the list | Offices in Belgium | Size by its own figures |
|---|---|---|---|
| Acerta (250) | Leuven | 26 | more than 70,000 companies |
| SD Worx (640) | Antwerp | 33 | 92,000 Belgian payroll clients |
| Securex (120) | Brussels | list without a total | 91,500 employers, group in 5 countries |
| Liantis (510) | Bruges | 60, for all services | 76,113 employers |
| Partena (300) | Brussels | 29 | 362,623 payslips a month |
All five have an office in Ghent, according to their own office lists.
And this is how they describe their price and their digital tools:
| Secretariat | Pricing model on its own website | Digital tools |
|---|---|---|
| Acerta | not described on the pages we consulted | Connect HR Office, Acerta Mobile App |
| SD Worx | tailored quote, based on headcount and needs | mysdworx, as a web application and mobile app |
| Securex | start-up fee and a fixed monthly management fee, tailored quote | Exact Officient with Self Service app, MySecurex |
| Liantis | entry fee, fixed price per month and fixed price per payroll calculation per employee | Lia+ |
| Partena | one-off entry fee and fixed price per payroll calculation per employee | ESS software with mobile app, SmartSalary |
The alternative: through a social bureau
Next to these five secretariats there is a different model: the social bureau. It is a local office that takes over your payroll administration and works with a recognised secretariat. It is not a social secretariat itself, so it does not appear in the tables above.
| Directly with a social secretariat | Through a social bureau | |
|---|---|---|
| Who processes the payroll? | the secretariat, based on the hours you enter yourself in its portal or app | the bureau collects and processes your hours, the secretariat behind it files the returns |
| Who is your contact? | a case manager or contact person at the secretariat | one fixed person at the bureau who knows your file |
| Where? | an office of the secretariat | the bureau's office, close to you |
| What does it cost? | on quotation | on quotation |
Acerta directly or through Business Centrum. Business Centrum is a social bureau in Ghent and recognised partner of Acerta. If you choose Acerta, you can join directly and work in Connect HR Office yourself, or go through us: Acerta remains your social secretariat, and we process your hours and are your fixed contact. Who does what, task by task, is set out in Acerta or Business Centrum.
An alternative to SD Worx, Securex, Liantis or Partena. With one of those four and want the work off your plate? Move to Acerta through Business Centrum. We arrange the switch with your current secretariat. Per provider: an alternative to SD Worx, Securex, Liantis or Partena. What a social bureau is, you can read in social bureau.
Acerta vs SD Worx: what are the differences?
Scale and region. SD Worx cites 92,000 Belgian clients who entrust their payroll to SD Worx. In Belgium it has at least 3,255 staff and 33 offices, and the group says it is active in more than 150 countries. Acerta describes itself as an HR services group in Belgium, with more than 2,000 employees in 26 offices in Flanders, Brussels and Wallonia. By its own figures, it makes more than 665,000 payroll calculations a month for more than 70,000 companies.
Services for an SME. SD Worx promises a fixed contact person and a team of 60 lawyers for legal questions. According to SD Worx, an SME is usually up and running within 4 to 6 weeks. Acerta puts a fixed regional payroll advisor first, who knows your sector and can call on lawyers per sector. Within the group, Acerta also has a social insurance fund for the self-employed and a business counter.
Digital tools. At SD Worx, the employer, team leaders and employees work in mysdworx, as a web application and a mobile app: payslips, leave, expenses and time registration. Viewing pay documents is included in the payroll price, according to SD Worx. Acerta offers Connect HR Office for the employer, including a module to register training with Sigedis, and the Acerta Mobile App in which employees request leave, submit expenses and view their pay documents.
Price. SD Worx writes that the cost depends on your headcount and your needs and draws up a tailored quote. Acerta does not describe its pricing structure on the pages we consulted.
If you have employees in other countries, ask both how they handle that in practice. If you only operate in Belgium, the contact person, the office near you and the price for your staff carry more weight.
Acerta vs Securex: what is different?
Securex says it is active in 5 countries and cites 91,500 employers who rely on the group, without a split by country or by service. That figure is therefore not directly comparable with Acerta's 70,000 companies.
Services. Securex combines the social secretariat with a social insurance fund, an online business counter and an external service for prevention and protection at work. Such an external service is compulsory from your first employee. More in our guide on the external prevention service. Acerta has a social insurance fund and a business counter.
Availability. Securex writes that its customer care is available every working day from 8 to 18 hours. Acerta gives no availability hours on the pages we consulted and puts its fixed regional payroll advisor first.
Digital tools. Securex offers Exact Officient, a cloud HR platform for SMEs with a Self Service app for employees. MySecurex is Securex's platform for accountants, where the shared client can also follow the file, with simulations of payroll cost and notice periods.
Price. Securex calls every quote tailor-made and describes two parts: a start-up fee after the switch and a fixed monthly price as a management fee.
Acerta vs Liantis: which is better?
There is no measurable criterion for better. Liantis does name a concrete amount: the licence price of its HR app Lia+.
Scale. Liantis has its head office in Bruges, more than 2,000 staff and 60 offices, for all the group's services together. The block "Liantis social secretariat in figures" shows 76,113 employers, and the same page says the secretariat supports more than 44,000 employers every day. In 2023, Liantis carried out 5,149,383 payroll calculations by its own figures, over the whole year.
Pricing model. Liantis speaks of an all-in rate: regular services, management fees and first-line legal advice are included in the price. You pay an entry fee for the switch, a fixed price per month and a fixed price per payroll calculation per employee.
Lia+. Liantis's HR app costs € 3.95 per employee per month, plus a one-off start-up fee of € 250. For the self-employed, freelancers, students and flexi-jobbers you pay no licence. Lia+ includes a digital time clock, an electronic signature with eID or itsme and a link to Monizze meal vouchers.
Worked example. A bakery with eight permanent employees and two flexi-jobbers pays 8 x 3.95 = € 31.60 a month for Lia+, or € 379.20 a year. In the first year the start-up fee is added: € 629.20 in total. That is the app licence, separate from the price of the social secretariat itself.
Acerta. Acerta works with a fixed regional payroll advisor who knows your sector, with 26 offices in the three regions. Its tools are Connect HR Office and the Acerta Mobile App. Both groups have a social insurance fund and a business counter. Liantis also has its own external service for prevention and well-being.
Acerta vs Partena: the differences
Scale. Partena Professional has its head office in Brussels, 1,747 staff and 29 offices in Belgium. The social secretariat cites 362,623 payslips a month, but no number of employers. Acerta cites more than 665,000 payroll calculations a month. A payslip and a payroll calculation are not always the same thing, so compare those two figures with care.
Advice and availability. Partena writes that 74 lawyers are on hand for clients' questions. On its page about switching, Partena promises that in 80% of cases you get your fixed contact person on the line straight away.
Switching. According to Partena, the switch is free and takes 6 months on average, counted from the moment your notice is confirmed. How a switch works and what notice your current contract requires is explained in changing social secretariat.
Digital tools. Partena has Employee Self Service software with a mobile app for leave, expenses and HR documents, and SmartSalary, a free tool to process wages, Dimona, flexi-jobs and students.
Price. Partena describes a one-off entry fee and a fixed price per payroll calculation per employee.
SD Worx vs Securex, and the other pairs
SD Worx vs Securex. Both are international groups. SD Worx counts its 92,000 clients for Belgium, Securex gives 91,500 employers for the whole group. Securex also provides an external prevention service and a social insurance fund. On the pages we consulted, SD Worx focuses on payroll, HR software and HR advice.
Securex vs Liantis. Both combine the social secretariat with a social insurance fund, a business counter and an external prevention service. Liantis describes three price components, Securex two.
Liantis vs Partena. Both charge a price per payroll calculation per employee. Liantis also charges a fixed price per month, Partena does not mention one. Partena cites 74 lawyers, Liantis first-line legal advice included in the price.
Securex vs Partena. Securex gives availability hours for its customer care, Partena an availability percentage for the fixed contact person. Both have a social insurance fund and a business counter.
Comparing social secretariats: five questions for every quote
- Who is my fixed contact person, and do they know my joint committee?
- What does it cost per year for my actual staff, with the entry fee, the price per payroll calculation and the services charged separately? Our guide on the cost of a social secretariat shows how that bill is built up.
- Which tool do my employees get, and is it included in the price?
- When can I start, given the notice period at my current secretariat and the start of the quarter?
- Which services come from the same group, such as an external prevention service or a social insurance fund for the managing director?
To see first how large each secretariat is and which other recognised secretariats exist, read the largest social secretariats in Belgium.
Rather have someone make this comparison for your business? Business Centrum puts your current contract next to a move to Acerta through us and tells you honestly what you gain.