
Limited statutory audit for engineering firms in Trogen explained simply
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on limited statutory audit in Trogen: what the law requires, what can be automated, and when to delegate.
Year-end closing: how the mechanics work
The closing turns day-to-day bookkeeping into annual accounts: balance sheet, income statement and notes (art. 958 CO). Mandatory stops: accruals and deferrals, depreciation, commercially justified provisions, inventory of stock and work in progress, then VAT and AHV reconciliations.
For limited statutory audit, a closing checklist reused every year transforms the exercise: same steps, same checks, same documents — only the year changes.
The Swiss legal frame for limited statutory audit
Three documents summarise the health of a Swiss business: the balance sheet (what it owns), the income statement (what it earns) and the notes (what else you should know). All the work of limited statutory audit converges on those three pages, in Trogen too.
Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For limited statutory audit, 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.
A well-structured SME chart of accounts
A good chart of accounts tells the story of the business: classes 1 and 2 describe what it owns and owes, class 3 what it sells, classes 4 to 6 what it consumes. Private accounts (sole proprietorships) and shareholder current accounts (Sàrl/SA) must stay spotless: they are the first thing examined in a tax audit.
For a business in Trogen, comparability over time beats sophistication: a chart stable for five years beats a “perfect” one rebuilt every year. Banks and the tax administration read year-on-year movements first.

A Swiss SME's accounting calendar
Every deadline has an owner: an obligation “of everyone” is kept by no one. Naming one person per deadline family (VAT, payroll, taxes) closes the gaps.
For limited statutory audit, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
Trogen: what changes, what does not
Working with a fiduciary from Trogen no longer depends on geography: the documents of a business in Trogen are shared online, while the canton Appenzell Outer Rhodes keeps its own deadlines for the tax return.
Trogen requires no special bookkeeping: the Code of Obligations applies at postal code 9043 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
Which social contributions does a Swiss employer pay?
AHV/IV/APG: 5.3% employer share (the same is withheld from the employee); unemployment insurance: 1.1% each up to CHF 148,200 a year; occupational pension (LPP) by age and plan (employer at least 50%); occupational accident insurance paid by the employer; family allowances by canton. For an employer in Trogen, family allowances follow the canton's rates.
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 Trogen too.
Effective VAT method or net tax rate: how to choose?
The effective method deducts actual input VAT and files quarterly; the net tax rate method applies a flat industry rate to turnover, semi-annually, with no separate input VAT deduction. The flat rate suits low-cost structures; as investments grow, the effective method usually wins again. The choice rests on the company's own figures, in Trogen as anywhere.
How long must records related to limited statutory audit 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 Trogen can therefore archive fully digitally.
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