
SA incorporation for architecture firms in Obermumpf: the practical guide
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on SA incorporation in Obermumpf: what the law requires, what can be automated, and when to delegate.
Choosing the structure: Sàrl, SA or sole proprietorship
Settling in Obermumpf 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.
Incorporating in Obermumpf opens the same toolbox: banks, funds, fiduciaries and online tools work everywhere — the choice of seat is strategic, not technical, for SA incorporation.
Swiss VAT: rates, threshold and filings
Taxable consideration is not limited to the invoiced price: barter, set-offs and benefits in kind count too. The safe reflex: every economic advantage received is documented and qualified.
The right reflex for SA incorporation: file every supplier invoice with its VAT on receipt. Forgotten input VAT is money definitively lost once the limitation period runs out.
Salaries and social contributions: the rates to know
Hiring the first employee triggers everything at once: affiliation to AHV and LPP funds, accident insurance, family allowances, working-time rules. A complete payroll file from day one avoids catch-ups.
For SA incorporation, the monthly payslip is only the visible part: instalments to the funds, annual settlements and certificates form the real cycle, January to January.

Digitalising SA incorporation: 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.
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.
Obermumpf: what changes, what does not
Obermumpf (postal code 4324, canton Aargau) applies the same federal rules as the rest of the country: what changes in Obermumpf are the cantonal counterparts — tax administration, compensation office, commercial register.
For a business in Obermumpf, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Aargau.
Frequently asked questions
How long must records related to SA incorporation 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 Obermumpf can therefore archive fully digitally.
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 Obermumpf too.
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 Obermumpf as anywhere.
Which social contributions does a Swiss employer pay?
AHV/IV/APG: 5.3% employer share (the same is withheld from the employee); unemployment insurance: 1.1% each up to CHF 148,200 a year; occupational pension (LPP) by age and plan (employer at least 50%); occupational accident insurance paid by the employer; family allowances by canton. For an employer in Obermumpf, family allowances follow the canton's rates.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates SA incorporation for businesses in Obermumpf: 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.