
Everything that matters about sole proprietorship deadlines in Kaiseraugst
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 Kaiseraugst.
Choosing the structure: Sàrl, SA or sole proprietorship
Chronologically, incorporation follows a precise thread: choose the form and the company name, pay the capital into an escrow account (Sàrl/SA), notarised deed, entry in the commercial register, then AHV affiliation and the VAT check. The Confederation's online desk (EasyGov) walks founders through these steps.
Incorporating in Kaiseraugst opens the same toolbox: banks, funds, fiduciaries and online tools work everywhere — the choice of seat is strategic, not technical, for sole proprietorship.
Digitalising sole proprietorship: what actually works
Access for the fiduciary, the auditor and employees is set by roles: view, enter, approve, close. Well-set rights protect the data and speed up collaboration.
Electronic archiving is fully recognised: Swiss bookkeeping regulation admits electronic retention of records provided integrity and readability are guaranteed for the 10 years of art. 958f CO. A paper binder is no longer an obligation — provided the archiving system is serious.
The Swiss legal frame for sole proprietorship
AHV audits and VAT audits follow the same logic: start from the documents, trace to the entries, check consistency. A business in Kaiseraugst with a clean audit trail sails through these exercises.
One simple principle drives sole proprietorship: every franc in or out must be explainable by a document, an entry and an account. All of Swiss accounting law fits inside that traceability requirement.

Salaries and social contributions: the rates to know
A Swiss salary reads in three columns: gross, employee social deductions, employer contributions. Confusing them distorts cost prices — and quotes from businesses in Kaiseraugst.
For sole proprietorship, the winning mechanics are simple: one single payroll database (salaries, rates, allowances), monthly slips generated from it, and an annual declaration that is little more than a sum. Painful catch-up invoices almost always stem from scattered data.
Kaiseraugst: what changes, what does not
Working with a fiduciary from Kaiseraugst no longer depends on geography: the documents of a business in Kaiseraugst are shared online, while the canton Aargau keeps its own deadlines for the tax return.
Federal deadlines do not move in Kaiseraugst: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 4303 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 Kaiseraugst too.
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 Kaiseraugst.
Which documents should be prepared for the year-end closing?
Bank and cash statements at the closing date, the inventory of stock and work in progress, final AHV/LPP/accident settlements, contracts signed or amended during the year, invoices straddling two years and the detail of accruals. With an up-to-date document archive, most of it is already there. The list is identical in Kaiseraugst: the CO dictates it, not the commune.
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 Kaiseraugst.
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Switch to accounting that keeps itself up to date
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