Only auditors may issue a C5 attestation, and the audit team's qualifications such as CISA, CISM, CCSK or ISO 27001 auditor must be listed in the attestation.

Checked 2026-10-02

Vendor
BSI
Product
C5
Subsystem
auditor requirements
Deployment
multi-tenant
Region
de
Release range
C5:2020 and C5:2026
Checked
2026-10-02

Sources

Cite this note

APA

WarmTransfer. (2026, October 2). UC and CCaaS security certifications: source note ucaas-compliance-certifications-c5-auditor-issues. WarmTransfer. https://warmtransfer.net/knowledge/claims/ucaas-compliance-certifications-c5-auditor-issues

BibTeX

@misc{warmtransfer-claim-ucaas-compliance-certifications-c5-auditor-issues,
  title  = {UC and CCaaS security certifications: source note ucaas-compliance-certifications-c5-auditor-issues},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/ucaas-compliance-certifications-c5-auditor-issues},
  note   = {Source note ucaas-compliance-certifications-c5-auditor-issues, checked 2026-10-02}
}

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