Updates
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This article was written by
Senior Consultant, National Office Tax & Legal
Certified Tax Advisor, Manager, National Office Tax & Legal
Electronic cash register systems must not only record sales reliably but also make their data available in full and in a machine-readable format for tax audits and unannounced cash register inspections. For this purpose, the tax authorities’ digital interface for cash register systems (Digitale Schnittstelle der Finanzverwaltung für Kassensysteme; DSFinV-K) specifies uniform file structures and data fields. While the technical security device (technische Sicherheitseinrichtung; TSE) protects records against undetected subsequent alterations, the DSFinV-K enables their standardised export. The German Federal Ministry of Finance (Bundesfinanzministerium; BMF) announced version 3.0 in the German Federal Finance Ministry circular dated October 30, 2026 (case no. IV D 2 – S 0316-a/00012/003/033). In coordination with this update, the BMF revised the Administrative Guidelines to the German Fiscal Code (Anwendungserlass zur Abgabenordnung; AEAO) concerning Section 146a of the German Fiscal Code (Abgabenordnung; AO) in the German Federal Finance Ministry circular dated October 26, 2026 (case no. IV D 2 – S 0316-a/00027/009/024).
One key change concerns transaction logging by the TSE: Once the new rules apply, each TSE transaction in cash register systems will consist of a start step and a completion step (German Federal Finance Ministry circular dated October 26, 2026, p. 18, paragraph 2.2.4). Updates using “UpdateTransaction” will no longer be required (ibid., p. 16, paragraph 2.2.2, item 2). This also removes the previous requirement to update the transaction at least every 45 seconds. The obligations to record individual transactions and retain records remain unaffected (ibid., pp. 11–12, paragraphs 1.15.2 to 1.15.4, and p. 15, paragraph 2.1.1).
Technical details are increasingly consolidated in the interface specifications. The previous detailed AEAO provisions on “cash register receipt” (Kassenbeleg), “order” (Bestellung) and “other transaction” (Sonstiger Vorgang) are replaced by references to Annex I of the DSFinV-K (ibid., pp. 17–18, paragraphs 2.2.3.5 to 2.2.3.6 and paragraph 2.2.4). Transaction types and data structures are defined there. Logging procedures for EU taximeters and distance counters are also being streamlined; the separate DSFinV-TW interface and its Annex B remain applicable to these devices (ibid., p. 23, paragraph 3.2.2, and p. 27, paragraph 4.2.2).
For cash register receipts, it is clarified that the signature counter for the completion of the transaction must be shown (ibid., p. 19, paragraph 2.4.4, item 8). The link between security-related receipt data and the transaction’s completion is also clarified (ibid., p. 19, paragraph 2.4.4). The existing requirement to reproduce the relevant data unchanged in the format returned by the TSE remains in place; subsequent rounding, truncation or alteration is still prohibited. The existing option to provide certain receipt information using a DSFinV-compliant QR code is consolidated in a separate subparagraph. This does not constitute a general exemption from receipt information requirements (ibid., pp. 19–20, paragraph 2.4.5).
DSFinV-K 3.0 must be applied to records created on or after January 1, 2029. It may be used voluntarily for records created on or after January 1, 2028. The revised AEAO will generally also apply from January 1, 2029. If the new interface version is used earlier, the revised AEAO must be applied at the same time. The two German Federal Finance Ministry circulars do not provide for any additional general transitional period or period during which non-compliance with the new requirements will not be challenged.
The new application dates do not affect the existing obligations concerning TSE protection, receipt issuance, record retention and notification of the tax office. Cash register notification must be distinguished from data export: For systems subject to notification requirements, the notification must generally be submitted within one month of acquisition or decommissioning; each notification must include all systems subject to notification requirements at the business establishment concerned.
Notice
Businesses should consult their cash register provider at an early stage to establish when DSFinV-K 3.0 will be supported, which adjustments are necessary and whether early adoption would be advisable. The systems and software versions in use, together with their assigned TSEs, should be documented, and a coordinated changeover date should be agreed.
Test exports and sample receipts should also be used to check whether business transactions, including cancellations, are provided in full and in a traceable manner and whether receipt information is correctly displayed. Businesses should ensure that historical records subject to retention requirements and TSE data remain available for analysis even after an update or system change; aggregation of the underlying records during the retention period is not permitted.
The procedural documentation must be updated specifically to reflect the processes that have actually changed. In particular, the changeover date, responsibilities, controls and test results must be documented. Notification and incident-handling procedures should also be reviewed: A TSE failure alone generally does not remove the obligation to issue receipts; the duration and cause of the failure must be documented, and the fault must be rectified without delay. This aligns the technical changeover with organisational procedures and improves traceability for tax audits.