Sole proprietorship for construction companies in Müllheim: the practical guide
Whether you run a Sàrl, an SA or a sole proprietorship in Müllheim, sole proprietorship eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
Choosing the structure: Sàrl, SA or sole proprietorship
Articles and internal organisation are written to last: circle of shareholders, transfer of shares, signature rights. Templates do the job at first, but every missing clause gets renegotiated later from a weaker position.
Settling in Müllheim 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
A VAT return is prepared, not endured: clean VAT accounts, one code per rate and a monthly variance check make the deadline trivial — for registered businesses in Müllheim too.
For an SME in Müllheim, 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, sole proprietorship stops being a quarterly chore.
Salaries and social contributions: the rates to know
Expense claims are payroll in the broad sense: actual reimbursements against receipts, or flat rates approved by the cantonal tax office in an expense policy. Without a clear rule, every reimbursement becomes a debate.
A thirteenth salary, where agreed, is accrued month by month — forget it and December reveals a charge of one-twelfth of the payroll, in Müllheim as everywhere.
Digitalising sole proprietorship: 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 Müllheim as everywhere.
The selection criterion for a tool is not the length of its feature list but the robustness of the daily flow: reliable bank imports, VAT computed correctly (8.1 / 2.6 / 3.8%), a complete audit trail from document to entry, and a clean export for the auditor or fiduciary. Everything else is secondary.
Müllheim: what changes, what does not
Working with a fiduciary from Müllheim no longer depends on geography: the documents of a business in Müllheim are shared online, while the canton Thurgau keeps its own deadlines for the tax return.
For a business in Müllheim, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Thurgau.
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 Müllheim too.
What are the legal obligations for sole proprietorship 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 Müllheim: federal law applies.
How long must records related to sole proprietorship be kept?
Ten years from the end of the financial year concerned (art. 958f CO). Electronic retention is permitted if the integrity and readability of the records are guaranteed — a serious digital archive validly replaces paper binders. A business in Müllheim can therefore archive fully digitally.
Does MyFiducia.ai work for a business based in Müllheim?
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 Müllheim manages its documents, VAT and exports exactly as anywhere in Switzerland.
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MyFiducia.ai automates sole proprietorship for businesses in Müllheim: 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.