
Bookkeeping deadlines in Aadorf: rules, deadlines, best practice
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 Aadorf.
The Swiss legal frame for bookkeeping
In Switzerland, the duty to keep accounts stems from art. 957 ff. of the Code of Obligations. Legal entities (Sàrl, SA) and sole proprietorships with at least CHF 500,000 in revenue keep full accounts: balance sheet, income statement and notes. Below that threshold, a simplified record of income, expenses and assets is sufficient.
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 bookkeeping run entirely on digital tools — no paper binder is required.
Digitalising bookkeeping: what actually works
A serious accounting document archive links every record to its entry, timestamps versions and logs access — exactly what Swiss bookkeeping regulation expects from probative electronic retention. Chronological filing by financial year becomes an automatic by-product.
For bookkeeping, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
A Swiss SME's accounting calendar
Three families of deadlines shape the year: federal (VAT within 60 days, salary declaration in January), cantonal (tax return, extensions depending on the canton, including in Aadorf) and internal (closing, general meeting within six months). Mixing them up is the leading cause of delays.
Handing deadline monitoring to a tool is no luxury: automatic reminders, a status per obligation, and an “all green” view that clears the mind. What matters is not who ticks the box — but that the box exists and everyone can see it.

A well-structured SME chart of accounts
Concretely, bookkeeping benefits from three tiers: balance-sheet accounts (classes 1-2) kept spotless for the closing, income accounts (classes 3-6) shaped for steering, and closing accounts (class 9) reserved for year-end entries. Each tier has its rhythm and its owner.
Standard numbering also enables automation: stable posting rules (same supplier, same account) make data entry predictable and the audit faster. Avoid changing the chart of accounts mid-year — migrate at the closing date, with a documented mapping table.
Aadorf: what changes, what does not
Working with a fiduciary from Aadorf no longer depends on geography: the documents of a business in Aadorf are shared online, while the canton Thurgau keeps its own deadlines for the tax return.
For a business in Aadorf, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Thurgau.
Frequently asked questions
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 Aadorf: the CO dictates it, not the commune.
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 Aadorf as anywhere.
Can bookkeeping 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 bookkeeping.
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 Aadorf too.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates bookkeeping for businesses in Aadorf: 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.