Keeping records digitally:ten years, readable and provable.

The retention periods the law sets

The starting point is art. 958f of the Swiss Code of Obligations. Accounting records, accounting vouchers, the annual report and the auditor’s report must be kept for ten years, and the period begins at the end of the financial year.^[3] For a financial year ending on 31 December 2026, the vouchers therefore run until the end of 2036. An invoice from January 2026 has to be kept for almost eleven years, one from December for barely ten. Anyone who clears out by document date rather than by financial year deletes too early.

VAT counts differently. Art. 70 para. 2 of the VAT Act requires books, vouchers, business papers and other records to be kept until the absolute statute of limitations for the tax claim takes effect, and it expressly reserves art. 958f CO.^[10] That absolute limit falls ten years after the end of the tax period in which the claim arose. The ordinary assessment limitation is five years and can be interrupted, the ten-year limit cannot.^[11] In practice the two periods coincide, only the starting point differs: the financial year in one case, the tax period in the other.

One exception stretches the period considerably. Business records needed to calculate the subsequent input tax deduction and own use of immovable property must be kept for twenty years.^[10] That reaches small businesses as soon as they buy a warehouse, convert a shop unit or use part of a building commercially. Importers should also keep customs law in view: data and documents used under the Customs Act must be kept carefully and systematically and protected against harmful effects.^[18]

The periods run side by side. In case of doubt the longer one applies, and it decides when a yearly folder may actually be deleted.

What belongs in the archive

Under art. 957a para. 3 CO an accounting voucher is any written record on paper or in electronic or comparable form that is needed to trace the transaction behind an entry.^[2] That definition is wider than most shop owners assume. What matters is not whether a document is paper, but whether the entry can still be explained without it.

In online retail that regularly covers:

• invoices and credit notes from the shop, including partial credits after returns
• payout reports from payment providers, because only they explain the gap between order value and the amount actually credited
• customs assessment decisions and forwarder statements on imports
• stocktaking lists and inventory valuations at the closing date
• agreements with suppliers where they justify an entry, such as rebates or annual bonuses
• logs from the shop and the accounting system where vouchers are generated or posted automatically^[7]

The duty does not depend on company size. Sole proprietorships and partnerships fall under full bookkeeping and financial reporting from CHF 500,000 of turnover in the previous financial year; below that, records of income, expenditure and the asset position suffice, with the principles of orderly bookkeeping applying by analogy.^[1] Such a business still has to retain the records that support its figures.

Paper, digital or both

Art. 958f para. 3 CO allows retention on paper, electronically or in a comparable manner, provided that correspondence with the underlying transactions is guaranteed and the records can be made readable again at any time.^[3] Those are two conditions, not one. The file has to match the transaction, and it has to open years later.

Only the annual report and the auditor’s report stay in writing and signed.^[3] Everything else may be paperless. VAT adds no separate regime: art. 122 of the VAT Ordinance refers the transmission and retention of paperless vouchers to art. 957 to 958f CO and to the accounting records ordinance.^[13] Meeting the commercial law requirements therefore meets the tax ones as well.

The direction of travel is clear. Since 1 January 2025, art. 123 of the VAT Ordinance prescribes the electronic procedure for registering as a taxable person, for filing the VAT return, for subsequent corrections and for the annual return, with further submissions following from 1 January 2027.^[14] The exchange with the authorities is digital; in many businesses the archive behind it is not.

What the accounting records ordinance requires

The detail sits in the ordinance on the keeping and retention of accounting records of 2002. It names no product and no software, only properties an archive has to have:

• Integrity. Books and vouchers must be kept and stored so that changes to them cannot go unnoticed.^[4]
• Documentation. Organisation, responsibilities, procedures and infrastructure must be set out in comprehensible working instructions, kept up to date and retained for as long as the books themselves.^[5]
• Availability. Authorised persons must be able to inspect and check the records within a reasonable time until the end of the period, and the staff and tools for that must remain available.^[6]
• Order in the archive. Archived information must be separated from current information or clearly marked, inventoried, protected against unauthorised access, and access must be logged. Those logs fall under the same retention duty.^[7]
• Checking and migration. Information media must be checked regularly for integrity and readability. Changing format or medium is allowed, but completeness, accuracy, availability and readability must be preserved, and the transfer must be logged.^[9]

Cloud, network drive, accounting software

Art. 9 GeBüV distinguishes two kinds of information media. Unmodifiable media such as paper, image carriers or write-once discs are permitted without further conditions. Modifiable media are permitted only where integrity is secured by technical procedures such as a digital signature, the moment of storage remains verifiable beyond doubt, for instance through a time stamp, the applicable rules are observed, and the procedures together with their logs are documented and retained. A medium counts as modifiable if changes or deletions cannot be proven.^[8]

That settles the most common practice in online retail. The federal SME portal states that storage in the cloud does not meet the condition for unmodifiable media and is therefore subject to the stricter requirements for modifiable media. It also recommends archival formats such as PDF/A and keeping the necessary devices and programmes available.^[16] A shared folder full of scans is not an archive as long as nobody can show when a file arrived there and that it has been unchanged since.

What counts is not where the file sits, but the proof that nothing was changed unnoticed.

None of this creates a signature requirement. The Federal Tax Administration states that it sees no need to demand qualified signatures for VAT purposes and that a voucher need not carry the electronic signature of a natural person. Other signatures and seals under the federal act on electronic signatures are equally suitable to show origin and integrity.^[15] Working without signatures is fine, as long as other robust traces exist: time stamps, test logs, audit-proof filing.

Retaining and deleting at the same time

The Swiss Data Protection Act requires personal data to be destroyed or anonymised as soon as it is no longer needed for the purpose of processing.^[17] That does not conflict with the retention duty, because a statutory duty is itself a purpose. It does call for a separation that many shops do not have.

Accounting vouchers stay for ten years because the law says so. Search histories, abandoned baskets, audience profiles, chat transcripts and newsletter clicks do not, because no such duty covers them. A business that keeps both in the same customer record ends up deleting either too much or too little. Two separate zones solve it: an archive with yearly folders for accounting, and live operations with their own deletion periods per data type. This article is an orientation and not legal or tax advice; a professional review is worth it for your own filing setup.

How to set the archive up

The work lies in the decisions, not in the technology. This order works well:

1. List your document types, from shop invoice through payout report to customs assessment, and note for each which system holds the original.
2. Choose formats that will still be readable in ten years, such as PDF/A for documents and CSV for extracts.^[16]
3. Secure integrity technically: a time stamp on filing, a change log, access rights by role.^[8]
4. Write the working instruction. Two pages are enough: who files, where, in which format, who checks and when, who may delete.^[5]
5. Close each yearly folder after the accounts are done and separate it from live operations, so that it is clear what counts as archive.^[7]
6. Once a year, open a sample, check readability and completeness and log the result.^[9]
7. Keep a deletion plan for personal data alongside it, with its own period per data type.^[17]

Almost everything that is manual today can be automated. Vouchers from the shop, the payment provider and the forwarder land in one store that sorts by financial year and document type, logs every arrival with time and origin, and links the entry in bexio or another system to the file. The yearly readability check becomes a task with a checklist and a log rather than a good intention. That is where core.iq starts: not with the archive as an end in itself, but with the chain from order to filed voucher.

Two points repay the effort in particular. First the payout reports from payment providers, because in an audit they bridge shop turnover and bank credit. Second the logs, because they are the only trace a modifiable medium leaves. Without them, only the free assessment of evidence remains, and that starts from zero.^[12]

Frequently asked questions