
Withholding tax guide in Arch: rules, deadlines, best practice
Whether you run a Sàrl, an SA or a sole proprietorship in Arch, 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
AHV audits and VAT audits follow the same logic: start from the documents, trace to the entries, check consistency. A business in Arch with a clean audit trail sails through these exercises.
Late books show from the outside: poorly calibrated tax instalments, provisional filings, slow answers to the bank. Staying current is also a matter of image.
Digitalising withholding tax: what actually works
Artificial intelligence has changed the economics of withholding tax: automatic invoice reading reaches recognition rates that make manual entry marginal, and posting suggestions learn from corrections. The accountant does not disappear — the job shifts from data entry to control and advice.
Migrate in stages: supplier invoices first (high volume, immediate gain), then receivables with the QR-bill, finally payroll and the closing. At each stage, comparing one month before/after is enough to prove the gain — no theoretical promises needed.
Outsource withholding tax or keep it in-house?
A good test before choosing: ask the fiduciary HOW it wants to receive the documents. A precise answer (formats, frequency, platform) says more than any brochure — including in Arch.
For withholding tax, the internal-external duo works when both sides see the same file: same entries, same documents, same deadlines. Misunderstandings are born from parallel copies.

A Swiss SME's accounting calendar
Three families of deadlines shape the year: federal (VAT within 60 days, salary declaration in January), cantonal (tax return, extensions depending on the canton, including in Arch) and internal (closing, general meeting within six months). Mixing them up is the leading cause of delays.
For withholding tax, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
Arch: what changes, what does not
Sole proprietorship, Sàrl or SA in Arch: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Bern.
Federal deadlines do not move in Arch: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 3296 changes nothing about those rules, only the sender's address.
Frequently asked questions
When is entry in the commercial register mandatory?
A Sàrl and an SA only come into existence with their registration. A sole proprietorship must register from CHF 100,000 of annual revenue; below that, registration stays voluntary but adds credibility and protects the business name. Registration goes through the canton's commercial register office — for Arch too.
Does MyFiducia.ai work for a business based in Arch?
Yes: the platform runs online, the rules applied are federal (VAT, CO, AHV), and the file can be shared with any fiduciary. A business in Arch manages its documents, VAT and exports exactly as anywhere in Switzerland.
What is simplified bookkeeping and who can use it?
Sole proprietorships and partnerships under CHF 500,000 of revenue may limit themselves to recording income, expenses and assets (art. 957 para. 2 CO). Once over the threshold — or upon founding a Sàrl or an SA — full accounts with balance sheet, income statement and notes become mandatory. The CHF 500,000 threshold is assessed the same way in Arch.
How long must records related to withholding tax be kept?
Ten years from the end of the financial year concerned (art. 958f CO). Electronic retention is permitted if the integrity and readability of the records are guaranteed — a serious digital archive validly replaces paper binders. A business in Arch can therefore archive fully digitally.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates withholding tax for businesses in Arch: 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.