--- title: "The 10 Criteria of Audit-Proof Archiving: A Practical Checklist" date: 2026-04-21T08:55:00+02:00 author: FAST LTA canonical_url: "https://www.fast-lta.de//en/blog/die-10-kriterien-der-revisionssicherheit-praxis-checkliste" section: "Entries: Articles" --- ### The 10 Criteria [\#](#the-10-criteria "The 10 Criteria") #### 1. Proper Retention [\#](#1-proper-retention "1. Proper Retention") - **Verification question:** Do you have documented retention policies per document type? - **Implementation:** Map each record type to its statutory period (set per member state; in Germany, for example, 10 years for commercial books and annual accounts, 8 years for accounting documents and invoices, 6 years for commercial correspondence since the 2025 reform). #### 2. Completeness [\#](#2-completeness "2. Completeness") - **Verification question:** Is every business transaction captured, with nothing lost on the way into the archive? - **Implementation:** Capture controls at every input channel, duplicate checks, reconciliation against source systems. #### 3. Earliest Possible Archiving [\#](#3-earliest-possible-archiving "3. Earliest Possible Archiving") - **Verification question:** Are records archived promptly after they arise? - **Implementation:** Automated, at least daily archiving processes; no documents parked on file shares for weeks. #### 4. Classification [\#](#4-classification "4. Classification") - **Verification question:** Is every document classified and enriched with metadata? - **Implementation:** A defined metadata structure (date, type, business partner, amount) and a maintained index. #### 5. Immutability [\#](#5-immutability "5. Immutability") - **Verification question:** Can data be modified or deleted after storage, by anyone, including administrators? - **Implementation:** Hardware WORM storage (for example Silent Cubes), where immutability is enforced by the system itself and cannot be bypassed with admin rights. Software locks alone shift the burden of proof to your organizational controls. #### 6. Loss Protection [\#](#6-loss-protection "6. Loss Protection") - **Verification question:** Does the archive survive hardware failure, fire, and ransomware? - **Implementation:** Redundant storage (Silent Cubes use erasure coding), geo-redundant replication for higher requirements, and air-gapped backups for the surrounding infrastructure. #### 7. Retrievability [\#](#7-retrievability "7. Retrievability") - **Verification question:** Can you find a specific invoice in under five minutes? - **Implementation:** DMS indexing and full-text search on top of the archive storage. #### 8. Reproducibility [\#](#8-reproducibility "8. Reproducibility") - **Verification question:** Can you still open and correctly render records after 10 or 20 years? - **Implementation:** Long-term archive formats (PDF/A, ISO 19005) and a format migration strategy. #### 9. Traceability [\#](#9-traceability "9. Traceability") - **Verification question:** Can an auditor trace each record from capture to archive? - **Implementation:** Audit logs, workflow documentation, and complete process documentation of the archiving procedure. #### 10. Auditability [\#](#10-auditability "10. Auditability") - **Verification question:** Can auditors access and evaluate the data with their own tools? - **Implementation:** Structured export interfaces and defined access modes for auditors (in Germany, for example, the tax authority’s direct, indirect, and data-carrier access modes). --- ### How to Use This Checklist [\#](#how-to-use-this-checklist "How to Use This Checklist") Work through all ten criteria once per year and after every system change. A single failed criterion breaks audit-proofness: an immutable archive that cannot produce a specific invoice fails just as hard as a perfectly indexed archive an admin can modify. The technology baseline for criteria 5 and 6 is hardware WORM with built-in redundancy; criteria 1 to 4 and 7 to 10 are process and DMS work on top. --- ### Further Resources [\#](#further-resources "Further Resources") → Audit-Proof Archiving Guide (/en/blog/revisionssicherheit-leitfaden/) → What Is Audit-Proof Archiving? (/en/blog/was-ist-revisionssicherheit/) → Audit-Proof Archiving vs. Immutability (/en/blog/revisionssicherheit-vs-unveraenderlichkeit/) → The 6 Most Common Mistakes in Audit-Proof Archiving (/en/blog/6‑fehler-revisionssichere-archivierung/) → Silent Cubes: Hardware WORM Archive Storage (/en/produkte/silent-cubes/) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### Audit-Proof Archiving Audit-proof archiving describes the legally required property of an archiving system that preserves documents completely, immutably, traceably and accessibly at all times — and that this can be demonstrated without gaps to tax authorities, auditors and data protection supervisory bodies. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/audit-proof-archiving) ### Audit-Proof Archiving Audit-proof archiving describes the legally required property of an archiving system that preserves documents completely, immutably, traceably and accessibly at all times — and that this can be demonstrated without gaps to tax authorities, auditors and data protection supervisory bodies. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/audit-proof-archiving) ### Audit-Proof Archiving Audit-proof archiving describes the legally required property of an archiving system that preserves documents completely, immutably, traceably and accessibly at all times — and that this can be demonstrated without gaps to tax authorities, auditors and data protection supervisory bodies. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/audit-proof-archiving) ### Audit-Proof Archiving Audit-proof archiving describes the legally required property of an archiving system that preserves documents completely, immutably, traceably and accessibly at all times — and that this can be demonstrated without gaps to tax authorities, auditors and data protection supervisory bodies. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/audit-proof-archiving) ### Immutable Storage Immutable storage refers to storage technologies that protect stored data from subsequent alteration or deletion — where the decisive difference lies in whether this protection is enforced at the hardware level (cannot be circumvented) or at the software level (can be circumvented by administrators with sufficient rights). [Mehr erfahren →](https://www.fast-lta.de//en/glossary/immutable-storage) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm) ### WORM WORM (Write Once, Read Many) refers to a storage principle in which data is written once and can technically no longer be altered or deleted — in hardware WORM, this immutability is a physical property of the storage controller, independent of software, operating system or user privileges. [Mehr erfahren →](https://www.fast-lta.de//en/glossary/worm)