KassenSichV and TSE
KassenSichV and TSE refer to Germany's Cash Register Anti-Tampering Ordinance and the Technical Security Device it mandates – a BSI-certified module that signs every POS transaction and thus protects it from later manipulation.
KassenSichV and TSE stand for the Cash Register Anti-Tampering Ordinance (Kassensicherungsverordnung) and the Technical Security Device (Technische Sicherheitseinrichtung) it prescribes. The KassenSichV is a statutory ordinance issued by the German Federal Ministry of Finance that, based on Section 146a of the Fiscal Code (Abgabenordnung, AO), specifies how electronic recording systems – above all cash registers – must be protected against manipulation. At the core of the requirement is the TSE: a component certified by the Federal Office for Information Security (BSI) that signs every POS transaction immediately and unalterably.
The aim of the Act on Protection Against Manipulation of Digital Basic Records is to technically prevent the subsequent deletion or alteration of cash takings. Since 1 January 2020, electronic cash register systems in Germany must generally be equipped with a TSE; in addition, there is an obligation to issue receipts and an obligation to report the systems in use to the tax office. This ties cash register management to the same principles of orderly record-keeping that GoBD and the Fiscal Code already apply to the rest of the accounting.
At a glance
- Legal basis: Section 146a AO in conjunction with the Cash Register Anti-Tampering Ordinance (KassenSichV)
- TSE = Technical Security Device: BSI-certified, signs every POS transaction in a tamper-proof way
- Three components of the TSE: security module, storage medium, digital interface (DSFinV-K)
- Obligations: TSE protection, receipt issuance duty and reporting of registers to the tax office
- Affects cash transactions in retail, hospitality and services – not every software register is automatically compliant
What KassenSichV and TSE regulate
The KassenSichV technically implements the "Act on Protection Against Manipulation of Digital Basic Records." It obliges businesses that use an electronic recording system for cash payment transactions to protect it with a certified Technical Security Device. This covers in particular electronic and PC cash registers, app and tablet registers, as well as POS systems that run as a module within an inventory management system.
Two further obligations flank the TSE. The receipt issuance duty requires that a receipt – digital or on paper – be created and made available to the customer for every business transaction; the customer is not obliged to take it. The reporting duty under Section 146a AO requires that the electronic recording systems in use, together with the TSE, be reported to the tax office. This report is submitted electronically via ELSTER.
How does a TSE work?
The Technical Security Device logs every single POS transaction at the moment it begins and ends. In doing so, it assigns the transaction a sequential signature counter, a transaction counter and a verified timestamp, and generates a cryptographic signature. Because the signature secures the content and the order of the transactions, any subsequent change or gap would stand out – manipulated or "vanished" takings become detectable this way.
The three components
A TSE consists of three functional elements. The security module generates the signatures and provides the counters and timestamps. The storage medium stores the secured records unalterably until they are exported. Finally, the standardized digital interface ensures that the data can be read out in a standardized format for the tax authorities.
Technically, the TSE is operated as a hardware solution (for example a USB stick, SD card, or as a module in the cash register server) or as a cloud TSE. Both variants must be certified by the BSI according to the underlying Technical Guideline; the certification is limited in time and must be renewed.
DSFinV-K and cash register inspection
The DSFinV-K (Digital Interface of the Tax Authorities for Cash Register Systems) applies to the export. It defines the data format in which individual records, master data and TSE signatures must be provided. In the course of an unannounced cash register inspection (Kassennachschau) under Section 146b AO, an inspector can request this data on site and check the TSE protection.
Failure and retention
If a TSE fails – for example due to a defect in the storage medium or a disruption of the cloud connection – cashiering may continue; however, the failure must be detected, documented and remedied promptly. During this phase, the receipt must indicate that the protection is temporarily missing. The secured records themselves are subject to the retention obligation: like other tax-relevant accounting documents, they must be kept unalterably for the statutory period and remain machine-readable in the DSFinV-K format, so that they can still be fully exported in a later tax audit.
Why KassenSichV and TSE matter
Cash-intensive sectors were long regarded as susceptible to turnover suppression using so-called zappers or phantomware – software that removes takings from the register after the fact. The TSE closes this gap by making the basic record tamper-proof at the moment it is created. For honest businesses, this creates legal certainty and robust evidential value of the cash register data vis-à-vis the tax office.
Violations are taken seriously: if a functioning TSE is missing or the reporting duty is ignored, fines may follow – and, in the case of disorderly cash register management, estimated additions to the tax base. Anyone taking cash payments should therefore not treat the compliance of the register in use as a mere software question, but document it as part of orderly bookkeeping.
KassenSichV and TSE in the ERP system
Many ERP and inventory management systems contain a cash register or POS module for point-of-sale selling. This module must connect the TSE and store the secured POS transactions together with the DSFinV-K data in an audit-proof manner. From there, the cash takings flow into financial accounting – classically via a posting export or a DATEV connection, so that cash register turnover is properly booked.
Whether a system works in a KassenSichV-compliant way does not depend on the vendor alone, but on TSE selection, configuration and the process documentation. This should describe which TSE is used, how receipts are issued and archived, and how the data export takes place during an inspection. Examples of systems with a cash register function in the DACH region can be found under "Related systems"; actual compliance must always be examined on a case-by-case basis. This article does not replace tax advice.
Distinction: KassenSichV, GoBD and RKSV
KassenSichV and GoBD interlock but are not the same. The GoBD are an overarching administrative directive on orderly, unalterable electronic bookkeeping and apply to all tax-relevant data. The KassenSichV is the more specific ordinance that concretizes these principles for electronic cash registers and, with the TSE, prescribes a particular technical protection. A cash register must therefore meet both requirements at the same time.
Within the DACH region, the German KassenSichV must not be confused with the Austrian regulation. Under the Cash Register Security Ordinance (Registrierkassensicherheitsverordnung, RKSV), Austria likewise requires a tamper-proof signature of every cash turnover, but uses its own procedure with a signature certificate and a QR code on the receipt. In Switzerland, there is no comparable obligation for technical cash register protection. Anyone selling across borders must consider the respective national regulation separately.
Example
Example: Café chain with ERP cash register module and cloud TSE
A café chain with five branches uses tablet registers at each location, connected as a module to its ERP system. Every order is secured via a cloud TSE: when a receipt is finalized, the TSE assigns a signature counter, timestamp and signature before the receipt is printed or provided digitally as a QR code. This fulfills the receipt issuance duty without paper necessarily having to be taken.
The cash register systems and their TSE were reported to the tax office via ELSTER. During an unannounced cash register inspection, the branch manager exports the daily data in DSFinV-K format directly from the ERP; the inspector recognizes from the gap-free counters that no takings were removed. Each month, the cash takings flow into the accounting via a DATEV export – the cash register management is considered orderly.
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