
Sole proprietorship for architecture firms in Thônex: the practical guide
Sole proprietorship for architecture firms in Thônex 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
Settling in Thônex does not change federal law, but the canton shapes what follows: profit and capital tax rates, family allowances, possible start-up support. Comparing seriously before fixing the seat can pay off — moving a company later costs more.
Sole proprietorship starts on day one: founding capital, notary and register fees are the first entries. Opening a separate business bank account immediately — even for a sole proprietorship — saves hours of sorting private from business.
The Swiss legal frame for sole proprietorship
A small business does not mean small obligations: from the first salary or the first VAT return, mistakes get expensive — in Thônex as anywhere.
Also worth knowing: accounts may be drawn up in the currency most relevant to the business; if that is not the franc, values must additionally be stated in CHF (art. 958d para. 3 CO). Internationally active companies gain books that match their economic reality.
Swiss VAT: rates, threshold and filings
Exports, services abroad, acquisition tax: as soon as anything international enters the picture, VAT gets demanding (place of supply, acquisition tax on services). Better to set the rules once with a professional than to correct three financial years.
The net tax rate method simplifies life for small structures: one flat industry rate applied to turnover, with semi-annual filing. In exchange, input VAT is not deducted separately. The effective-versus-flat-rate choice should be reviewed periodically against the cost structure.

Salaries and social contributions: the rates to know
The salary certificate is an official tax document: it feeds the employee's tax return and serves as the reference in AHV and tax audits. Issued once a year, it must match payroll accounting and the declaration to the compensation office to the centime.
An employer in Thônex does well to fix payday on a set day of the month: funds, employees and cash flow organise around it, and sole proprietorship becomes routine instead of a sprint.
Thônex: what changes, what does not
Sole proprietorship, Sàrl or SA in Thônex: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Geneva.
Federal deadlines do not move in Thônex: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 1226 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 Thônex.
Does MyFiducia.ai work for a business based in Thônex?
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 Thônex manages its documents, VAT and exports exactly as anywhere in Switzerland.
Do you need a fiduciary for sole proprietorship, or can you do it yourself?
Both are defensible. Below CHF 500,000 of revenue, a sole proprietorship may keep simplified accounts itself. As soon as payroll, VAT and a closing with tax stakes are involved, professional support prevents mistakes that cost more than the fees. With a shared platform, the fiduciary does not even need to be in Thônex.
How much does sole proprietorship cost in Thônex?
It depends on document volume, the number of salaries and VAT complexity — no serious figure can be quoted without examining the file. Two levers cut the bill everywhere: digitised, well-filed receipts and software that prepares entries instead of having them re-keyed.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates sole proprietorship for businesses in Thônex: 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.