
Sole proprietorship for IT companies in Birmensdorf (ZH) without the stress: how it works
Swiss accounting law (art. 957 ff. of the Code of Obligations) sets a precise frame, yet day-to-day practice often stays fuzzy. This guide walks through what actually matters for a business based in Birmensdorf (ZH).
Choosing the structure: Sàrl, SA or sole proprietorship
Settling in Birmensdorf (ZH) 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.
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
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.
A thirteenth salary, where agreed, is accrued month by month — forget it and December reveals a charge of one-twelfth of the payroll, in Birmensdorf (ZH) 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 Birmensdorf (ZH) as everywhere.
The winning pair for sole proprietorship: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.

The Swiss legal frame for sole proprietorship
In Switzerland, the duty to keep accounts stems from art. 957 ff. of the Code of Obligations. Legal entities (Sàrl, SA) and sole proprietorships with at least CHF 500,000 in revenue keep full accounts: balance sheet, income statement and notes. Below that threshold, a simplified record of income, expenses and assets is sufficient.
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.
Birmensdorf (ZH): what changes, what does not
Birmensdorf (ZH) (postal code 8903, canton Zurich) applies the same federal rules as the rest of the country: what changes in Birmensdorf (ZH) are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Birmensdorf (ZH): VAT within 60 days, salary declaration in January, 10-year record retention — postal code 8903 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 Birmensdorf (ZH) 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 Birmensdorf (ZH) 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 Birmensdorf (ZH), family allowances follow the canton's rates.
Do you need a fiduciary for sole proprietorship, 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 Birmensdorf (ZH).
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Switch to accounting that keeps itself up to date
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