
Fiduciary services in Switzerland in Aristau: what every SME should know
Whether you run a Sàrl, an SA or a sole proprietorship in Aristau, fiduciary services eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
The Swiss legal frame for fiduciary services
Whether a business sits in Aristau or elsewhere in Switzerland, the same federal law applies — one of the strengths of the Swiss system for fiduciary services. Cantonal differences concentrate on taxation (rates, filing deadlines); bookkeeping itself follows art. 957 ff. CO everywhere.
The law also settles the form: accounts may be kept in a national language or in English, on paper or electronically (art. 957a para. 5 CO). That pragmatism lets fiduciary services run entirely on digital tools — no paper binder is required.
Outsource fiduciary services or keep it in-house?
The Swiss fiduciary market is dense and governed by professional practice: industry standards, business secrecy, civil liability. Compare offers on three concrete criteria — exact scope (data entry? closing? payroll? VAT?), a named contact person, and the tools used. It prevents year-end misunderstandings.
A business in Aristau can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — fiduciary services splits very well.
Year-end closing: how the mechanics work
The income statement reads as a cascade: gross margin, operating result, financial result, extraordinary result. Each level answers a different question — mixing levels blurs the steering.
The timetable is tight: accounts drawn up and approved by the general meeting within six months of the year-end. For fiduciary services, chasing missing documents from January (bank statements, contracts, insurance settlements) avoids the last-minute sprint and auditor reservations.

Digitalising fiduciary services: 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.
The winning pair for fiduciary services: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.
Aristau: what changes, what does not
Aristau (postal code 5628, canton Aargau) applies the same federal rules as the rest of the country: what changes in Aristau are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Aristau: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5628 changes nothing about those rules, only the sender's address.
Frequently asked questions
Do you need a fiduciary for fiduciary services, 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 Aristau.
What are the legal obligations for fiduciary services in Switzerland?
The foundation is the Code of Obligations: proper bookkeeping (art. 957a CO), annual accounts (balance sheet, income statement, notes) and 10-year retention of books and records (art. 958f CO). VAT applies from CHF 100,000 of turnover, and social insurance settlements from the first employee. Nothing is different in Aristau: federal law applies.
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 Aristau.
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 Aristau too.
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