SA incorporation for architecture firms in Seengen without the stress: how it works
SA incorporation for architecture firms in Seengen 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.
Choosing the structure: Sàrl, SA or sole proprietorship
Settling in Seengen does not change federal law, but the canton shapes what follows: profit and capital tax rates, family allowances, possible start-up support. Comparing seriously before fixing the seat can pay off — moving a company later costs more.
First accounting reflex for SA incorporation: open the document numbering with the very first expense, even before registration. Founding costs are deductible — if documented.
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.
For SA incorporation, 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.
The Swiss legal frame for SA incorporation
Three documents summarise the health of a Swiss business: the balance sheet (what it owns), the income statement (what it earns) and the notes (what else you should know). All the work of SA incorporation converges on those three pages, in Seengen too.
The annual accounts (art. 958 CO) consist of the balance sheet, the income statement and the notes; they must be drawn up within six months of the year-end so the general meeting can approve them. A delay here cascades into the tax return and the final social insurance settlements.
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 Seengen too.
A business in Seengen that crosses the threshold mid-year must register without delay: retroactive registration with interest always costs more than signing up on time.
Seengen: what changes, what does not
Working with a fiduciary from Seengen no longer depends on geography: the documents of a business in Seengen are shared online, while the canton Aargau keeps its own deadlines for the tax return.
Federal deadlines do not move in Seengen: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5707 changes nothing about those rules, only the sender's address.
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 Seengen 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 Seengen 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 Seengen.
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 Seengen: federal law applies.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates SA incorporation for businesses in Seengen: 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.