Collecting data is easy, deleting it on time is not. Without a deletion concept, data stores grow without limit, and with them the risk in a data breach and the effort for every access request.
Legal basis
The FADP requires personal data to be destroyed or anonymised as soon as it is no longer needed for the purpose of processing (Art. 6(4) FADP). The GDPR sets out the storage limitation principle and a right to erasure. Statutory retention duties stand against this, in Switzerland for example the ten-year retention of business records and vouchers under the Code of Obligations or retention duties under the Anti-Money Laundering Act.
Content
A deletion concept assigns each data category a purpose, a retention period with legal basis or reasoning, a starting point for the period, the responsible unit and the method of deletion or anonymisation. The basis is the record of processing, which already contains the categories.
Backups and archives
Data in backups can rarely be deleted selectively. It is therefore common for backups to be overwritten on a fixed rotation and for restored data to be checked against the deletion list before use. This rule belongs explicitly in the concept.
Implementation and proof
A deletion concept only works once technically implemented: automatic deletion routines in systems, regular deletion runs with logs and a check that they actually happen. For new systems, deletion belongs in the requirements, not a later retrofit, in the spirit of privacy by design.