
Sole proprietorship in Switzerland in Birrwil explained simply
Delegate, digitalise or do it all yourself? Around sole proprietorship in Birrwil, 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
A Sàrl requires CHF 20,000 of fully paid-in capital; an SA CHF 100,000 of which at least CHF 50,000 paid in. Both require a notarised deed and entry in the commercial register. A sole proprietorship arises from mere activity — registration only becomes mandatory from CHF 100,000 of annual revenue.
On taxes, corporate profit bears direct federal tax at 8.5% (statutory rate) plus cantonal and communal tax — the total effective burden varies markedly between cantons. A realistic business plan and accounts kept from the start make bank credit noticeably easier.
Salaries and social contributions: the rates to know
Two of these contributions are set by law: AHV/IV/APG at 5.3% and unemployment at 1.1%, both payable by the employer. The others — LPP, accident insurance, possibly daily sickness benefits and family allowances — depend on the insurer, the industry and the pension plan. The total surcharge usually falls between 12 and 20% of gross pay, and employee deductions between 10 and 15%: these are orders of magnitude, not statutory rates.
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
Digitising does not mean hoarding PDFs: without the document-entry link, a digital file is as opaque as a box of archives — true in Birrwil as everywhere.
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.

The Swiss legal frame for sole proprietorship
Whether a business sits in Birrwil or elsewhere in Switzerland, the same federal law applies — one of the strengths of the Swiss system for sole proprietorship. Cantonal differences concentrate on taxation (rates, filing deadlines); bookkeeping itself follows art. 957 ff. CO everywhere.
Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For sole proprietorship, that means in practice: no movement without a receipt, and an audit trail that can be reconstructed at any time — including during a VAT or AHV inspection.
Birrwil: what changes, what does not
Birrwil (postal code 5708, canton Aargau) applies the same federal rules as the rest of the country: what changes in Birrwil are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Birrwil: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5708 changes nothing about those rules, only the sender's address.
Frequently asked questions
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 Birrwil 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 Birrwil, family allowances follow the canton's rates.
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 Birrwil too.
What is simplified bookkeeping and who can use it?
Sole proprietorships and partnerships under CHF 500,000 of revenue may limit themselves to recording income, expenses and assets (art. 957 para. 2 CO). Once over the threshold — or upon founding a Sàrl or an SA — full accounts with balance sheet, income statement and notes become mandatory. The CHF 500,000 threshold is assessed the same way in Birrwil.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates sole proprietorship for businesses in Birrwil: 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.