
Fiduciary services for law firms in Windisch: 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 fiduciary services in Windisch: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for fiduciary services
Responsibility for the books is personal: in an SA, organising the accounting is one of the board's non-transferable duties (art. 716a CO); in a Sàrl, the managing directors carry the same duty. Outsourcing the execution never transfers that underlying responsibility, including for a company based in Windisch.
The good news: the Swiss frame is stable and predictable. Structure fiduciary services once — chart of accounts, document flow, calendar — and the same organisation pays off for years.
Digitalising fiduciary services: 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.
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.
A Swiss SME's accounting calendar
Extensions exist and can be requested: cantonal deadlines for the tax return, deferral of the VAT filing on a reasoned request. But an extension does not stop interest: on VAT, default interest runs from the ordinary due date even when more time has been granted.
For fiduciary services, two dates lock themselves in every year: the January salary declaration and the general meeting within six months — everything else is planned around them.

Year-end closing: how the mechanics work
Depreciation follows rates accepted by tax practice (property, machinery, IT): staying within those ranges avoids reassessments. Exceeding them is justified — and documented, in Windisch as anywhere.
A company in Windisch that presents clean, punctual annual accounts gains credibility — with its bank, its suppliers and the tax administration.
Windisch: what changes, what does not
Working with a fiduciary from Windisch no longer depends on geography: the documents of a business in Windisch are shared online, while the canton Aargau keeps its own deadlines for the tax return.
Windisch requires no special bookkeeping: the Code of Obligations applies at postal code 5210 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
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 Windisch as everywhere in Switzerland.
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 Windisch.
Can fiduciary services 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 fiduciary services.
How long must records related to fiduciary services 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 Windisch can therefore archive fully digitally.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates fiduciary services for businesses in Windisch: 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.