Tax compliance : registered cash register, FDM and black box
The fiscal module is not bolted on afterwards: it is part of the act of taking payment. Here is how it works, what it signs and what happens when something goes wrong.
Short answer
IZIII embeds a fiscal data module (FDM) in the payment flow: the till composes the operation, presents it to the black box, the box signs it, and the signature comes back onto the receipt with the control QR code. Five fiscal operations are handled — sale, pro forma, copy, refund and transfer — and the module identifier is configurable per point of sale.
The registered cash register system in two minutes
The registered cash register system (SCE in French, geregistreerd kassasysteem or GKS in Dutch, commonly the « white till ») is the arrangement required in Belgium for certain hospitality businesses. It combines two inseparable elements :
- A till software that records every operation in a standardised format.
- A fiscal data module that signs those operations in a tamper-proof way and keeps non-modifiable counters.
The receipt handed to the customer carries the data produced by that signature. The purpose of the arrangement is simple : to make retroactive deletion of a sale technically impossible.
What an FDM is
The FDM (Fiscal Data Module) is the device connected to the till — what the trade familiarly calls the black box. It contains a personalised smart card, the VSC (VAT Signing Card), which identifies the business.
| Element | Role |
|---|---|
| IZIII till | Composes the operation: lines, quantities, VAT rates, totals, operation type, user identifier. |
| FDM | Receives the operation, signs it, increments its counters and returns the signature together with the data to be printed. |
| VSC | Personalised smart card: identifies the taxable person and holds the cryptographic signing material. |
| VAT receipt | Carries the signature, the counters and a QR code allowing the operation to be checked. |
In IZIII, the fiscal module identifier is configurable per point of sale. A venue with several tills connected to several FDMs therefore addresses the right module for each operation, with no ambiguous global configuration.
The fiscal operations
A fiscal till does more than record sales. It has to qualify every event, including those that involve no payment at all.
| Operation | When | Effect |
|---|---|---|
| Sale | Payment of an order. | Signing of the operation and issue of the VAT receipt. |
| Pro forma | The customer asks for the bill before paying. | A non-fiscal document signed as such, distinct from the final sale. |
| Copy | Reprint of a receipt already issued. | Document identified as a copy; the original receipt is never reissued identically. |
| Refund | Cancellation after payment. | A signed negative operation, traced and carried into the reports. |
| Transfer | Moving an order from one table to another. | A signed transfer operation, keeping the audit trail continuous. |
Where the signature happens
This is a design point more than a technical detail : the signature is not a deferred process run after the fact. It is part of the act of taking payment.
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The order is frozen
The basket is resynchronised with the server-side order, and totals and VAT are recalculated. A stale amount cannot be signed.
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The operation is presented to the FDM
Operation type, lines, rates, totals and user identifier are sent to the fiscal module of the relevant point of sale.
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The signature comes back
The module returns the signature and its counters. That data is attached to the order.
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The receipt is printed
The print engine inserts the fiscal data into the receipt template through dedicated macros, including the control QR code.
What happens when there is an error
A network that drops, a device without power, a timeout : these things happen mid-service. The point is not to prevent them, but never to let them pass unnoticed.
- The order moves to a dedicated « FDM error » status, visible in the back office and on the till screens alike.
- The status is visually distinct in the order list.
- A manual retry lets the operation be re-presented to the module once it is reachable again.
- Nothing is considered signed until the signature has come back.
Reports and journal
Compliance does not stop at the receipt : it means being able to reconstruct the activity.
- Fiscal reports printable directly from the till.
- Numbered X, Y and Z till reports, with a breakdown by payment method.
- Configurable financial reports, filterable by period, point of sale or status, exportable and sendable automatically by e-mail.
- Journal of sensitive operations: cancellations, discounts, refunds, reprints, with author and timestamp.
- Traceability of items removed after being sent to production, in the form of cancellation lines.
Certification framework
In Belgium, a till + FDM combination is subject to a certification procedure structured on two levels : a mandatory base — core test set, rounding tests, reports and cross-cutting checks — and an advanced level matching the features declared by the vendor.
The IZIII fiscal module is developed and tested against that framework, with a test plan covering the whole set of mandatory-base use cases as well as the advanced scenarios matching the till's features.
Personal data and hosting
IZIII runs on your own instance. Orders, customers and the catalogue live in your database, on the hosting of your choice.
- The till itself imposes no mandatory transit through a third-party platform.
- Only the services you switch on communicate with the outside world: payment terminal, delivery platform, fiscal module.
- Access is governed by user profiles and a rights table: every front-end screen is protected by a named permission.
- Sensitive actions are logged with their author, which makes responding to traceability obligations easier.
- You remain the data controller under the GDPR; hosting within the European Economic Area is a matter for your choice of provider.
Tax compliance : the recurring questions
What is the Belgian registered cash register system?
It is the arrangement required in Belgium for certain hospitality businesses. It combines till software recording every operation in a standardised format and a fiscal data module signing them in a tamper-proof way while keeping non-modifiable counters.
The receipt handed to the customer carries that signature data. Falling within scope and the applicable thresholds are matters for the Belgian tax administration: check your situation with your accountant.
What is an FDM or black box?
The FDM (Fiscal Data Module) is the device connected to the till. It contains a personalised smart card, the VSC, which identifies the taxable person. The till composes the operation, the FDM signs it and increments the counters, and the signature ends up on the receipt with a control QR code.
Which fiscal operations does the IZIII till handle?
Sale, pro forma, copy, refund and table transfer. Each is qualified and signed as such, including those that involve no payment, so that the audit trail stays continuous.
What happens if the black box does not respond?
The operation is not silently validated. The order moves to a dedicated « FDM error » status, visually distinct in the lists, and a manual retry lets the operation be re-presented once the module is reachable again.
Can I use IZIII outside Belgium?
Yes. The Belgian fiscal module is specific to Belgian hospitality; the rest of the platform works anywhere. For Luxembourg, France, the Netherlands, Italy and Spain the local framework is examined case by case.
Unsure about your fiscal setup?
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