
Sole proprietorship for architecture firms in Birsfelden without the stress: how it works
Sole proprietorship for architecture firms in Birsfelden rests on three pillars: federal law that applies across Switzerland, cantonal deadlines worth knowing, and tools that eliminate re-keying. This guide puts it all in order, fact by fact.
Choosing the structure: Sàrl, SA or sole proprietorship
Check the company name before any enthusiasm: availability in the commercial register, internet domain, possible trademark. Renaming later costs time and trust, in Birsfelden as elsewhere.
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.
The Swiss legal frame for sole proprietorship
For an owner in Birsfelden, the question is never “do we need accounts?” but “at what level of detail?”. The CO sets the floor; the bank, the tax office and the shareholders set the rest.
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.
Salaries and social contributions: the rates to know
The salary certificate is an official tax document: it feeds the employee's tax return and serves as the reference in AHV and tax audits. Issued once a year, it must match payroll accounting and the declaration to the compensation office to the centime.
For sole proprietorship, the monthly payslip is only the visible part: instalments to the funds, annual settlements and certificates form the real cycle, January to January.

Digitalising sole proprietorship: 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.
For an SME in Birsfelden, the real gain of digitalised sole proprietorship shows day to day: no paper pile at month-end, VAT prepared continuously, and an owner reading today's figures rather than last quarter's.
Birsfelden: what changes, what does not
Working with a fiduciary from Birsfelden no longer depends on geography: the documents of a business in Birsfelden are shared online, while the canton Basel-Country keeps its own deadlines for the tax return.
Federal deadlines do not move in Birsfelden: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 4127 changes nothing about those rules, only the sender's address.
Frequently asked questions
Can sole proprietorship be automated with AI?
Largely, yes: automatic document reading, posting suggestions, bank reconciliation via QR references and VAT exports. Human approval remains essential — AI prepares, the professional checks. That is exactly how MyFiducia.ai approaches sole proprietorship.
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 Birsfelden as anywhere.
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 Birsfelden.
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 Birsfelden.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates sole proprietorship for businesses in Birsfelden: 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.