The C5 was fundamentally revised in 2019 in dialogue with users, auditors, regulators and cloud providers and completed as a new version in January 2020. The BSI would like to thank all those involved for their cooperation and extensive comment as part of the public community draft.

The final version of the C5:2020 includes many innovations compared to the previous version.

For test periods ending on or after 15 February 2021, the BSI recommends that 2020 version C5:2020 be applied in order to take sufficient account of current developments.