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SA incorporation for SMEs in Sommeri without the stress: how it works

Delegate, digitalise or do it all yourself? Around SA incorporation in Sommeri, every SME draws its own line. The reference points below — federal law, cantonal practice and lessons from the field — help you place the cursor well.

Choosing the structure: Sàrl, SA or sole proprietorship

Partners from day one? A shareholders' agreement settles what the articles do not: exit, deadlock, valuation. Signing it while everything is fine costs an evening; negotiating it in a crisis costs the company.

Settling in Sommeri also means thinking about insurance from incorporation: professional liability, property, business interruption — the accounts keep track of them and the closing allocates them correctly.

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.

For an SME in Sommeri, electronic filing of VAT returns has been mandatory since 1 January 2025; the tax administration's online portal is also where extensions are requested and past periods consulted. Combined with accounts that prepare the return automatically, SA incorporation stops being a quarterly chore.

Digitalising SA incorporation: 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 — true in Sommeri as everywhere.

The winning pair for SA incorporation: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.

Handshake during a business meeting, top view

The Swiss legal frame for SA incorporation

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. SA incorporation sits squarely within this frame, including for companies based in Sommeri.

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.

Sommeri: what changes, what does not

Sole proprietorship, Sàrl or SA in Sommeri: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Thurgau.

Sommeri requires no special bookkeeping: the Code of Obligations applies at postal code 8580 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.

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. These federal thresholds do not depend on the registered seat — in Sommeri as anywhere.

Do you need a fiduciary for SA incorporation, 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 Sommeri.

What are the legal obligations for SA incorporation in Switzerland?

The foundation is the Code of Obligations: proper bookkeeping (art. 957a CO), annual accounts (balance sheet, income statement, notes) and 10-year retention of books and records (art. 958f CO). VAT applies from CHF 100,000 of turnover, and social insurance settlements from the first employee. Nothing is different in Sommeri: federal law applies.

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 Sommeri too.

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