
Sole proprietorship for SA companies in Duillier: what every SME should know
Sole proprietorship for SA companies in Duillier raises the same questions for most Swiss SME owners: which obligations apply, which deadlines are running, which documents to prepare. This page covers the federal rules in force — without unnecessary jargon.
Choosing the structure: Sàrl, SA or sole proprietorship
Chronologically, incorporation follows a precise thread: choose the form and the company name, pay the capital into an escrow account (Sàrl/SA), notarised deed, entry in the commercial register, then AHV affiliation and the VAT check. The Confederation's online desk (EasyGov) walks founders through these steps.
On taxes, corporate profit bears direct federal tax at 8.5% (statutory rate) plus cantonal and communal tax — the total effective burden varies markedly between cantons. A realistic business plan and accounts kept from the start make bank credit noticeably easier.
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, including in Duillier. They come on top of the federal social insurances and appear on every payslip.
Withholding tax applies to foreign employees without a C permit: the employer deducts tax at the cantonal rate and remits it. The annual salary certificate remains mandatory for all staff — it is the linchpin connecting payroll accounting, tax returns and AHV audits.
Digitalising sole proprietorship: what actually works
A serious accounting document archive links every record to its entry, timestamps versions and logs access — exactly what Swiss bookkeeping regulation expects from probative electronic retention. Chronological filing by financial year becomes an automatic by-product.
Electronic archiving is fully recognised: Swiss bookkeeping regulation admits electronic retention of records provided integrity and readability are guaranteed for the 10 years of art. 958f CO. A paper binder is no longer an obligation — provided the archiving system is serious.

The Swiss legal frame for sole proprietorship
Responsibility for the books is personal: in an SA, organising the accounting is one of the board's non-transferable duties (art. 716a CO); in a Sàrl, the managing directors carry the same duty. Outsourcing the execution never transfers that underlying responsibility, including for a company based in Duillier.
For sole proprietorship, the classic early mistake remains mixing private and business: a dedicated bank account and documented private withdrawals eliminate half the discussions with the tax office.
Duillier: what changes, what does not
Duillier (postal code 1266, canton Vaud) applies the same federal rules as the rest of the country: what changes in Duillier are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Duillier: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 1266 changes nothing about those rules, only the sender's address.
Frequently asked questions
What are the current Swiss VAT rates?
Since 1 January 2024: 8.1% (standard), 2.6% (reduced — for example food and medicines) and 3.8% (accommodation). Returns must be filed and paid within 60 days after the period ends (quarterly under the effective method, semi-annually under the net tax rate method). These federal rates apply unchanged in Duillier.
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 Duillier too.
Does MyFiducia.ai work for a business based in Duillier?
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 Duillier 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 Duillier.
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