
Social security contributions for construction companies in Dornach: what every SME should know
Social security contributions for construction companies in Dornach 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.
The Swiss legal frame for social security contributions
AHV audits and VAT audits follow the same logic: start from the documents, trace to the entries, check consistency. A business in Dornach with a clean audit trail sails through these exercises.
Late books show from the outside: poorly calibrated tax instalments, provisional filings, slow answers to the bank. Staying current is also a matter of image.
A Swiss SME's accounting calendar
January: salary declaration to the compensation office and salary certificates. End of February, May, August, November: quarterly VAT returns (effective method), each to be filed and paid within 60 days after the quarter ends. Within six months of year-end: approved annual accounts. Then: the tax return under cantonal deadlines, with extensions possible.
For social security contributions, two dates lock themselves in every year: the January salary declaration and the general meeting within six months — everything else is planned around them.
Outsource social security contributions or keep it in-house?
Responsibility stays with the client: the fiduciary executes with care, but the signed accounts bind the company. Understanding what you sign is not optional.
A clear mandate agreement states who does what by when: document handover, posting deadlines, filing calendar, and responsibility for delays. A shared platform (same data, same document archive) between the company and its fiduciary eliminates binder ping-pong and duplicate entry.

Salaries and social contributions: the rates to know
Absences are managed upstream: illness, accident, military service or maternity trigger allowances (APG, insurance) that replace part of the salary. Clean absence records are the basis of correct settlements, in Dornach as elsewhere.
For social security contributions, the practical challenge is the calendar: AHV instalments during the year, salary declaration to the compensation office in January, salary certificates for staff, and final LPP/accident settlements. A clean payroll base avoids unpleasant catch-up invoices.
Dornach: what changes, what does not
Sole proprietorship, Sàrl or SA in Dornach: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Solothurn.
Dornach requires no special bookkeeping: the Code of Obligations applies at postal code 4143 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
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 Dornach 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 Dornach as anywhere.
Does MyFiducia.ai work for a business based in Dornach?
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 Dornach manages its documents, VAT and exports exactly as anywhere in Switzerland.
What are the legal obligations for social security contributions 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 Dornach: federal law applies.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates social security contributions for businesses in Dornach: 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.