
Everything that matters about SA incorporation for construction companies in Troistorrents
Swiss accounting law (art. 957 ff. of the Code of Obligations) sets a precise frame, yet day-to-day practice often stays fuzzy. This guide walks through what actually matters for a business based in Troistorrents.
Choosing the structure: Sàrl, SA or sole proprietorship
A Sàrl requires CHF 20,000 of fully paid-in capital; an SA CHF 100,000 of which at least CHF 50,000 paid in. Both require a notarised deed and entry in the commercial register. A sole proprietorship arises from mere activity — registration only becomes mandatory from CHF 100,000 of annual revenue.
A Sàrl and an SA must also appoint an auditor, unless they opt out (no more than ten full-time positions on annual average and unanimous shareholder consent). Many young companies start without one, then appoint an auditor when growth or investors demand it.
The Swiss legal frame for SA incorporation
For an owner in Troistorrents, the question is never “do we need accounts?” but “at what level of detail?”. The CO sets the floor; the bank, the tax office and the shareholders set the rest.
Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For SA incorporation, 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.
Swiss VAT: rates, threshold and filings
Registration happens with the Federal Tax Administration and yields a VAT number based on the business identifier (format CHE-xxx.xxx.xxx VAT). From then on, every invoice must state that number, the rate applied and the tax amount — three details SA incorporation should lock down from day one to avoid retroactive fixes.
A business in Troistorrents that crosses the threshold mid-year must register without delay: retroactive registration with interest always costs more than signing up on time.

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 Troistorrents does well to fix payday on a set day of the month: funds, employees and cash flow organise around it, and SA incorporation becomes routine instead of a sprint.
Troistorrents: what changes, what does not
Sole proprietorship, Sàrl or SA in Troistorrents: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Valais.
Troistorrents requires no special bookkeeping: the Code of Obligations applies at postal code 1872 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
Which social contributions does a Swiss employer pay?
AHV/IV/APG: 5.3% employer share (the same is withheld from the employee); unemployment insurance: 1.1% each up to CHF 148,200 a year; occupational pension (LPP) by age and plan (employer at least 50%); occupational accident insurance paid by the employer; family allowances by canton. For an employer in Troistorrents, family allowances follow the canton's rates.
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. The list is identical in Troistorrents: the CO dictates it, not the commune.
How much does SA incorporation cost in Troistorrents?
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.
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 Troistorrents.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates SA incorporation for businesses in Troistorrents: 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.