# BSI C5:2020 — overview

- Source: https://support.icompaas.com/support/solutions/articles/a_gen_overview_bsic5-bsi-c52020-overview
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [BSI C5 (German Cloud)](https://support.icompaas.com/support/solutions/c_gen_bsi_c5) › [Overview](https://support.icompaas.com/support/solutions/folders/f_gen_cgenbsic5_overview)
- Last updated: 2026-05-30
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

BSI C5:2020 · 121 criteria across 17 domains, attestation under ISAE 3000

### What is it?

The **Cloud Computing Compliance Criteria Catalogue (C5)**, published by Germany's **BSI**, defines minimum requirements for cloud-service providers to be considered trustworthy for German customers. It is widely required in regulated sectors (finance, healthcare, public administration) and in tenders run by German federal & state governments.

### How it is delivered

C5 is an **attestation standard**: an accredited auditor performs an examination under **ISAE 3000** (or IDW PS 951) and issues a Type 1 (design) or Type 2 (operating effectiveness, typically 6–12 months) report. The report covers both the criteria themselves and the cloud provider's **transparency information** (data location, subcontractors, investigation requests).

### The 17 domains

Organisation of information security, security policies, HR, asset management, physical security, operations, identity & access management, cryptography & key management, communication security, portability & interoperability, procurement / development / change management, control & monitoring of service providers and suppliers, security incident management, business continuity, compliance and data protection, and dealing with investigation requests.

### "Basic" and "Additional" criteria

Every domain has _basic_ criteria (the floor) and _additional_ criteria (deeper assurance — used by customers with elevated trust requirements). Many German tenders require additional criteria for specific domains (e.g., cryptography, identity).

### Crossovers

C5 maps closely to ISO/IEC 27001 and 27017; a mature ISMS gets you ~70% of the way. The German-specific differentiators are _data location transparency_, _jurisdiction_, and _government investigation request handling_.

### How iCompaas helps

iCompaas provides the C5:2020 criteria mapped to evidence sources, a transparency-information template (data centres, subcontractors, response process), and a workflow to compile the auditor's evidence pack at the end of an attestation window.

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.