
Sole proprietorship with AI in Frenkendorf: rules, deadlines, best practice
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on sole proprietorship in Frenkendorf: what the law requires, what can be automated, and when to delegate.
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.
A Sàrl and an SA must also appoint an auditor, unless they opt out (no more than ten full-time positions on annual average and unanimous shareholder consent). Many young companies start without one, then appoint an auditor when growth or investors demand it.
Swiss VAT: rates, threshold and filings
Registration happens with the Federal Tax Administration and yields a VAT number based on the business identifier (format CHE-xxx.xxx.xxx VAT). From then on, every invoice must state that number, the rate applied and the tax amount — three details sole proprietorship should lock down from day one to avoid retroactive fixes.
Input VAT deduction is the flip side of VAT charged: tax paid on purchases and investments comes back through the return, receipt in hand. Rigorous entry of supplier invoices therefore translates directly into cash.
Salaries and social contributions: the rates to know
Absences are managed upstream: illness, accident, military service or maternity trigger allowances (APG, insurance) that replace part of the salary. Clean absence records are the basis of correct settlements, in Frenkendorf as elsewhere.
A thirteenth salary, where agreed, is accrued month by month — forget it and December reveals a charge of one-twelfth of the payroll, in Frenkendorf as everywhere.

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 Frenkendorf with a clean audit trail sails through these exercises.
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.
Frenkendorf: what changes, what does not
Frenkendorf (postal code 4402, canton Basel-Country) applies the same federal rules as the rest of the country: what changes in Frenkendorf are the cantonal counterparts — tax administration, compensation office, commercial register.
For a business in Frenkendorf, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Basel-Country.
Frequently asked questions
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 Frenkendorf.
When must a business register for VAT?
As soon as its worldwide annual turnover reaches CHF 100,000 (CHF 250,000 for non-profit sports or cultural associations). Below that, voluntary registration remains possible and often makes sense to reclaim input VAT on investments. The threshold is federal: it applies in Frenkendorf as everywhere in Switzerland.
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 Frenkendorf.
How long must records related to sole proprietorship 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 Frenkendorf can therefore archive fully digitally.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates sole proprietorship for businesses in Frenkendorf: AI-read documents, posting suggestions, VAT and exports ready for your fiduciary. Try the platform or browse our other guides.
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