GoBD

Immutable storage with cryptographic hash chaining, 10-year retention on WORM storage, auto-generated Verfahrensdokumentation, and IDEV-ready export for German tax authorities.

Cryptographic hash chain
1
TX-001a3f4···8e2c
links to a3f4···8e2c
2
TX-002b7d1···4f9a
links to b7d1···4f9a
3
TX-003c9e2···1d6b
SHA-256 · tamper-evident

Cryptographic hash chain.

Every transaction — sales, invoices, payments, refunds — is linked to the previous one via a SHA-256 hash. Each record stores the hash of the prior record, creating a tamper-evident chain. Modifying any record breaks the chain and is immediately detectable during integrity verification.

10-year retention on WORM storage
2024
2026
2036

Records

48,210

Earliest

Jan 2024

WORM

No delete

10-year retention on WORM storage.

GoBD requires records to be retained for 10 years in a form that prevents alteration or deletion. Cronos stores all records on WORM (Write Once, Read Many) storage. No record can be modified or deleted during the retention period, and the full chain remains verifiable for the entire duration.

Verfahrensdokumentation

verfahrensdokumentation.pdf

Auto-generated · Aug 6, 2026

POS sales process
Online checkout flow
Hash chain storage
Export procedures
PDFXMLUpdated on system changes

Verfahrensdokumentation, auto-generated.

GoBD requires a Verfahrensdokumentation — a technical documentation describing how electronic records are created, stored, and secured. Cronos generates this document automatically, covering all POS and online sales processes. It is updated when the system changes and available as PDF for audits.

Integrity verification
100%
Records checked48,210
Chain intactYes ✓
Broken links0
Last verifiedAug 6, 2026
Re-verify on demand · log stored

Integrity verification on demand.

The entire hash chain can be verified at any time. The integrity check walks every record from the first to the latest, confirming that each hash links correctly. The result — total records checked, chain intact, broken links — is logged and available as proof for tax authorities.

GoBD export for tax authorities
gobd_export_2024_2026/
index.xml
transactions/
sales_2024.xml
sales_2025.xml
sales_2026.xml
invoices/
invoices_2024.xml
checksum.sha256
1.2 GBHash verified
IDEV-ready

GoBD export for tax authorities.

Export the full record set in the format required by German tax authorities: XML files with an index.xml manifest, hash values, and a checksum file. The export is import-ready for IDEV (the digital audit tool used by Finanzamt). Your tax advisor can download it directly.

Frequently asked questions

What is GoBD and who does it apply to?

GoBD (Grundsätze zur ordnungsmäßigen Führung und Aufbewahrung von Büchern, Aufzeichnungen und Unterlagen in elektronischer Form sowie zum Datenzugriff) are German principles for the proper management and storage of electronic books and records. They apply to any business in Germany that keeps electronic accounting records.

What is a hash chain and why is it needed?

A hash chain links each transaction to the previous one using a SHA-256 cryptographic hash. If any record is modified after the fact, the chain breaks and the tampering is immediately detectable. This proves to tax authorities that records have not been altered since creation.

How long must records be retained under GoBD?

10 years from the end of the calendar year in which the record was created. During this period, records must be stored in a way that prevents modification or deletion. Cronos uses WORM storage to enforce this — no record can be altered or removed during the retention period.

What is a Verfahrensdokumentation?

It is a technical document describing how electronic records are created, processed, and stored. GoBD requires it for any business using electronic accounting systems. Cronos generates it automatically and keeps it updated when the system changes. It is available as PDF for audits.

Can I verify the integrity of my records myself?

Yes. The integrity verification function walks the entire hash chain from the first record to the latest. It confirms that every link is intact and no record has been tampered with. The result is logged with a timestamp and can be presented to auditors.

What format is the GoBD export?

The export contains XML files for each record type, an index.xml manifest listing all files, and a checksum file. This format is compatible with IDEV, the digital audit tool used by German tax authorities. Your tax advisor can download the export as a ZIP archive.

Does Cronos support the Z3 data access method?

Yes. GoBD defines three data access methods: B1 (read on screen), B2 (direct download), and Z3 (full digital audit via structured export). The GoBD export with index.xml and checksums satisfies the Z3 requirement, allowing tax authorities to perform a fully digital audit.

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