
Sole proprietorship in Switzerland in Sommeri explained simply
Delegate, digitalise or do it all yourself? Around sole proprietorship 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.
On the sole proprietorship side, the first financial year may be longer or shorter than a calendar year: choosing the first closing date wisely avoids a pointless mini-closing.
The Swiss legal frame for sole proprietorship
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. Sole proprietorship sits squarely within this frame, including for companies based in Sommeri.
The good news: the Swiss frame is stable and predictable. Structure sole proprietorship once — chart of accounts, document flow, calendar — and the same organisation pays off for years.
Salaries and social contributions: the rates to know
Every salary paid in Switzerland triggers joint contributions: AHV/IV/APG at 10.6% in total, i.e. 5.3% borne by the employer and 5.3% withheld from the employee; unemployment insurance at 2.2% (1.1% each) up to CHF 148,200 of annual salary. Add occupational pension (LPP credits of 7 to 18% of the coordinated salary depending on age, employer at least 50%), accident insurance (occupational accidents paid by the employer) and family allowances.
An often underestimated point: self-employed status is granted by the compensation office — or not. Whoever invoices essentially one main client risks requalification as an employee, with contribution arrears charged to the principal. Clarifying AHV status before starting avoids that trap.

Digitalising sole proprietorship: what actually works
Security is part of digitalisation: named access, tested backups, encryption of sensitive data. A digital accounting file is protected like a safe — because it is one.
For sole proprietorship, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
Sommeri: what changes, what does not
Working with a fiduciary from Sommeri no longer depends on geography: the documents of a business in Sommeri are shared online, while the canton Thurgau keeps its own deadlines for the tax return.
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
When must a business register for VAT?
As soon as its worldwide annual turnover reaches CHF 100,000 (CHF 250,000 for non-profit sports or cultural associations). Below that, voluntary registration remains possible and often makes sense to reclaim input VAT on investments. The threshold is federal: it applies in Sommeri as everywhere in Switzerland.
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.
Effective VAT method or net tax rate: how to choose?
The effective method deducts actual input VAT and files quarterly; the net tax rate method applies a flat industry rate to turnover, semi-annually, with no separate input VAT deduction. The flat rate suits low-cost structures; as investments grow, the effective method usually wins again. The choice rests on the company's own figures, in Sommeri as anywhere.
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 Sommeri: the CO dictates it, not the commune.
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