GKS 2.0 and FDM requirements in Belgium
Belgium first introduced its fiscalization system with a focus on the HoReCa (hotels, restaurants, and catering) sector in 2015.
HoReCa Businesses exceeding a set revenue threshold have since been required to use the Geregistreerd Kassasysteem (GKS), or Registered Cash Register System, which combines a certified POS system, a Fiscal Data Module (FDM), and a Virtual Smart Card (VSC) to securely record each transaction. This hardware-based setup helped ensure data integrity and accountability during on-site inspections by the Belgian tax authorities (FPS Finance).
Now, more than a decade later, Belgium is preparing for the next step: GKS 2.0, a modernized system similar to digitalized approaches in other European countries that will introduce real-time reporting of sales data to the FPS.
Fiscalization in Belgium so far: The Registered Cash Register System (GKS) and Fiscal Data Module (FDM)
Belgium’s fiscalization system currently applies to the HoReCa sector (hotels, restaurants, and catering). Businesses with on-premise sales exceeding 25,000€ are required to use the certified cash register GKS (Geregistreerd Kassasysteem).
Under the existing setup, fiscal compliance is achieved through three main components:
- a certified POS system (GKS),
- a Fiscal Data Module (FDM) that securely stores and signs all transaction data, colloquially known as Black Box (Zwarte Doos or Boîte Noire)
- a Virtual Smart Card (VSC) linked to the merchant’s VAT number.
Transaction data is stored locally within the FDM, and tax authorities perform on-site inspections to verify compliance and transaction integrity. For every transaction, the GKS must generate a receipt, which is then provided to the customer.
The Geregistreerd Kassasysteem (GKS) or Système de Caisse Enregistreuse (SCE)
The Registered Cash Register System (GKS or SCE) is Belgium’s fiscalization framework designed to ensure transparent and tamper-proof transaction reporting in the HoReCa sector. It requires eligible businesses to use a certified POS system that connects to a Fiscal Data Module (FDM) and a Virtual Smart Card (VSC).
Together, these components record, sign, and securely store every sale, creating a digital audit trail that tax authorities can verify during inspections. The GKS was introduced to combat tax evasion and guarantee that all on-premise sales are accurately declared to FPS Finance.
While effective in ensuring compliance, the system’s reliance on physical hardware components has led to operational challenges, paving the way for the more flexible, cloud-based GKS 2.0.
The Fiscal Data Module (FDM)
The Fiscal Data Module (FDM) is a key component of Belgium’s GKS fiscalization system, it is also known as Black Box, Zwarte Doos, or Boîte Noire.
It serves as a secure hardware device responsible for recording, signing, and storing all transaction data generated by the POS system. Each sale is digitally signed using a unique cryptographic key, ensuring that the transaction cannot be altered or deleted once recorded.
The FDM acts as a local safeguard for fiscal data, allowing FPS Finance to verify the authenticity and completeness of sales during on-site inspections.
The Virtual Smart Card (VSC)
The Virtual Smart Card (VSC) is a digital security component within Belgium’s GKS system that links a business’s fiscal device to its unique VAT identification number. It replaces the need for a physical smart card by securely managing the cryptographic keys used to sign transactions and authenticate the merchant.
Each transaction recorded by the POS and stored in the Fiscal Data Module (FDM) is digitally signed through the VSC, ensuring that every sale can be traced back to the correct taxpayer. In essence, the VSC guarantees the authenticity, traceability, and accountability of fiscal data within the GKS framework.
The next step for tax compliance in Belgium: GKS 2.0 and real-time reporting
Belgium is currently in the process of modernizing its approach. With the introduction of GKS 2.0 (or SCE 2.0), the country is moving toward a more digitalized fiscalization model.
Planned key changes include:
- The updated FDM will operate without a card and will transmit data in real-time directly to the tax authorities (FPS) – both the FDM and the POS must be certified,
- The possibility to issue digital receipts,
- Improved transaction processing speed for businesses and auditors alike
- Communication to the FPS Finance cloud and secure storage, minimizing the need for on-site inspections.
Originally scheduled for mid-2025, the introduction of GKS 2.0 has been postponed to January 1, 2026 for new businesses.
Existing businesses already using SCE 1.0 will switch to SCE 2.0 gradually, starting July 1, 2026, depending on when their current system was installed.
The Belgian government is also considering broadening the scope of GKS 2.0, potentially making its use mandatory for other sectors beyond the HoReCa industry. However, no details have been published yet.
