
Withholding tax online explained simply
Whether you run a Sàrl, an SA or a sole proprietorship, withholding tax eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
The Swiss legal frame for withholding tax
Swiss accounting law has been unified in the Code of Obligations since 2013: the same bookkeeping rules (art. 957a CO) and retention rules (art. 958f CO — 10 years for books, vouchers and reports) apply regardless of legal form. Withholding tax sits squarely within this frame.
Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For withholding tax, that means in practice: no movement without a receipt, and an audit trail that can be reconstructed at any time — including during a VAT or AHV inspection.
Outsource withholding tax or keep it in-house?
Splitting roles clearly avoids duplication: the company captures documents and approves payments; the fiduciary checks postings, closes the year and defends the file before the authorities. Each side does what it does best — and nobody keys the same invoice twice.
For withholding tax, a quarterly 30-minute check-in with the fiduciary beats an annual marathon: questions get handled while they are small.
Salaries and social contributions: the rates to know
Family allowances are financed by the employer through a cantonal compensation fund — rates and amounts vary from canton to canton. They come on top of the federal social insurances and appear on every payslip.
A thirteenth salary, where agreed, is accrued month by month — forget it and December reveals a charge of one-twelfth of the payroll.

A Swiss SME's accounting calendar
An accounting calendar only lives if it is shared: owner, in-house bookkeeper and fiduciary must see the same deadlines and the same status.
An SME that holds its calendar twelve months straight changes its position: fewer official reminders, easier extensions — and withholding tax stops being a source of worry.
Digitalising withholding tax: what actually works
Digitising does not mean hoarding PDFs: without the document-entry link, a digital file is as opaque as a box of archives.
For withholding tax, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
Frequently asked questions
What is the difference between a limited and an ordinary audit?
The ordinary audit applies to companies exceeding, for two consecutive years, two of three thresholds: CHF 20 million balance sheet total, CHF 40 million revenue, 250 full-time positions. Others fall under the limited audit, and those with no more than ten full-time positions on annual average can opt out with all shareholders' consent.
Which documents should be prepared for the year-end closing?
Bank and cash statements at the closing date, the inventory of stock and work in progress, final AHV/LPP/accident settlements, contracts signed or amended during the year, invoices straddling two years and the detail of accruals. With an up-to-date document archive, most of it is already there.
Can withholding tax be automated with AI?
Largely, yes: automatic document reading, posting suggestions, bank reconciliation via QR references and VAT exports. Human approval remains essential — AI prepares, the professional checks. That is exactly how MyFiducia.ai approaches withholding tax.
Does MyFiducia.ai work for a business anywhere in Switzerland?
Yes: the platform runs online, the rules applied are federal (VAT, CO, AHV), and the file can be shared with any fiduciary. Cantonal specifics (taxes, allowances) are configured in your file.
Also worth reading
This guide by municipality
Switch to accounting that keeps itself up to date
MyFiducia.ai automates withholding tax for Swiss SMEs: AI-read documents, posting suggestions, VAT and exports ready for your fiduciary. Try the platform or browse our other guides.
The application is operated in French.