Cash-register security & TSE: what restaurateurs must know

Cash-register security refers to the legal requirement that digital records of business transactions can no longer be changed or deleted unnoticed after the fact. The legal basis is Section 146a of the German Fiscal Code (Abgabenordnung, AO) together with the Cash Register Security Ordinance (KassenSichV). The legislator's aim is to prevent tax evasion through manipulated tills. This topic is especially relevant for hospitality, where many cash transactions occur.

• Every single transaction – for example a coffee sold or a table receipt – must be recorded completely and in an unalterable way.
• The records must be secured by a certified technical security device (TSE, technische Sicherheitseinrichtung).
• Data must always be readable, traceable and exportable for the tax authority.
• There is no general obligation to use an electronic register at all – an open cash drawer remains permissible in principle.
• However, as soon as you choose an electronic register system, the TSE and recording duties apply in full.

The key distinction is this: the duty does not arise from the mere existence of your business, but from the type of register you use. Anyone who voluntarily or for practical reasons uses a POS system also takes on the full cash-register security obligations. This article serves as general orientation and is not legal advice.

The technical security device (TSE) is the heart of cash-register security. It is integrated into the register system and cryptographically signs every transaction, so that subsequent changes become detectable. A TSE must be certified by Germany's Federal Office for Information Security (BSI). It can be implemented as a hardware module or as a cloud solution.

What a certified TSE must do

• It signs every transaction with a time stamp and a consecutive number, so any gaps would stand out.
• It stores the data in a tamper-proof format that the tax authority can inspect.
• It enables the export of secured data in a standardised, uniform format (DSFinV-K).
• It must be certified to BSI requirements and must be operated and kept up to date on an ongoing basis.
• The records must comply with the GoBD – the principles of proper digital bookkeeping.

The KassenSichV specifies which electronic recording systems are affected and how the TSE must be designed technically. As a rule, your cash register or POS provider is responsible for supplying or integrating a suitable certified TSE. When selecting a register system, explicitly clarify whether a valid certified TSE is included and who takes care of updating it and renewing the certificates.

Beyond the TSE, there are further duties around the electronic register. These include the receipt-issuance duty, the reporting of the systems in use to the tax office, and the unannounced cash audit (Kassennachschau). These points interlock and should be considered from the start.

1. 1Receipt-issuance duty: for every transaction, a receipt must be made available to the guest immediately – this may also be electronic. The guest is not required to take the receipt with them.
2. 2Register reporting duty: electronic recording systems with a TSE must be reported to the tax office; check the currently prescribed deadline and the reporting procedure, as these requirements can change.
3. 3Cash audit: the tax authority may appear unannounced and check the compliance of your register on site.
4. 4Data export: on request, you must be able to provide the data secured by the TSE in the prescribed format.
5. 5Documentation: keep manuals, programming logs and TSE evidence in an orderly way so that you can provide information during an audit.

The cash audit in particular shows how important a consistently correct setup is: it takes place without notice during business hours. Anyone who has configured their register cleanly, issues all receipts correctly and can export the data is well positioned here. You should always verify specific deadlines and procedures with the tax office or your tax adviser, keeping the current details in mind.

The good news: with the right software and a clear approach, cash-register security is manageable. The decisive point is not to shoulder the responsibility alone, but to work closely with your register provider and your tax adviser. The following points help you tackle the topic in a structured way.

• Check whether your current cash register or POS system includes a valid, BSI-certified TSE and who is responsible for maintaining it.
• Make sure receipt issuance works automatically – whether on paper or digitally.
• Clarify the reporting and retention duties and the applicable deadlines with your tax adviser.
• Test the data export (DSFinV-K) so that you can provide information quickly during a cash audit.
• Keep software and TSE certificates up to date and document changes to the register configuration.
• Draw a clear line between register functions and other digital tools in your business, so each task is handled by the right system.

If you run an open cash drawer, different recording requirements apply – but here too, income must be documented completely and traceably. Which option makes sense for your business depends on size, receipt volume and ways of working. When in doubt, seek advice from a qualified tax adviser.

Honesty matters here: gastronomx is not a cash register and not a POS solution – and it does not provide a TSE. Cash-register security, the TSE and the associated data export must run through an approved, TSE-secured register system. So for the till itself you still need a suitable, KassenSichV-compliant provider.

What gastronomx covers

gastronomx takes care of the digital guest side of your business: digital menu and QR menu, website, reservations, online ordering and reviews – multilingual and centrally in one place. These areas complement your register system but do not replace it. The till stays with the specialised POS provider, while gastronomx neatly bundles guest contact, your public presence and your digital workflows.

When it comes to connecting gastronomx with a cash register, you will find further guidance in our help topic on integrations and cash-register systems. For all questions about the specific TSE and KassenSichV obligations, your register provider together with your tax adviser is the right contact. This article serves as general orientation and does not replace legal or tax advice.