Accounting records must comply with the Code of Obligations.
Article 958f of the Swiss Code of Obligations stipulates that accounting books and records as well as annual and audit reports must be retained for ten years. The retention period begins as of the fiscal year-end. A printed and signed copy of the annual and audit reports must be retained.
Accounting books and records may be retained on paper, electronically or in any equivalent form, provided that access to the transactions and other relevant data can be guaranteed and the records are accessible at all times. The Federal Council has issued regulations in the Ordinance for keeping and retaining accounting records (in German: GeBüV).
Non-modifiable electronic data
GeBüv Article 9 stipulates that electronic data is permitted, with no additional requirements, as long as it is non-modifiable, i.e. if it cannot be altered or deleted without such changes being detectable on the electronic data carrier itself (e.g. non-modifiable CDs or DVDs).
Any authorized person must be able to inspect and audit the books and records at any time and within a reasonable period until the end of the retention period. The necessary equipment and programs must therefore be available. Certain file formats are more suitable than others for long-term storage. For example, the Federal Archives have defined for their own needs formats adapted to archiving (in German) that guarantee the readability of digital documents in the long term.
Most accounting, billing, payroll and other software programs can generate files suitable for archiving (e.g. PDF/A - Portable Document Format Archive), which can then be burned onto non-modifiable data carriers (CD, DVD, etc.). Cloud backup does not meet this requirement and is subject to the more stringent requirements for modifiable electronic data.
Modifiable electronic data
The Ordinance on bookkeeping stipulates that modifiable data carriers are also permitted subject to certain conditions. In such cases, technical procedures, such as electronic signatures, must be used to ensure the integrity of the recorded information. The time at which the information was recorded must be verifiable without any possibility of falsification (e.g. by time stamping). Information such as protocols, log files, etc. must also be retained. A number of software packages that are available include these features.
Criteria imposed by the law governing value-added tax (VAT)