
Limited statutory audit for engineering firms in Thürnen: the practical guide
Delegate, digitalise or do it all yourself? Around limited statutory audit in Thürnen, every SME draws its own line. The reference points below — federal law, cantonal practice and lessons from the field — help you place the cursor well.
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.
A company in Thürnen that presents clean, punctual annual accounts gains credibility — with its bank, its suppliers and the tax administration.
A Swiss SME's accounting calendar
Tax instalments are steered: too low, they set up a salty final bill; too high, they tie up cash. Adjusting them on current figures is a profitable reflex, in Thürnen as anywhere.
For a business in Thürnen, an isolated delay can be caught up; a structural delay is paid in interest, fines and stress. The difference between the two: a system, not good intentions.
Outsource limited statutory audit or keep it in-house?
Splitting roles clearly avoids duplication: the company captures documents and approves payments; the fiduciary checks postings, closes the year and defends the file before the authorities. Each side does what it does best — and nobody keys the same invoice twice.
Changing fiduciary is not a drama: the accounting data belongs to the company, and a clean export (entries, chart of accounts, linked documents) allows a transition at year-end. A provider who locks in a client's data says a lot about how it works.

The Swiss legal frame for limited statutory audit
Swiss accounting law has been unified in the Code of Obligations since 2013: the same bookkeeping rules (art. 957a CO) and retention rules (art. 958f CO — 10 years for books, vouchers and reports) apply regardless of legal form. Limited statutory audit sits squarely within this frame, including for companies based in Thürnen.
For limited statutory audit, the classic early mistake remains mixing private and business: a dedicated bank account and documented private withdrawals eliminate half the discussions with the tax office.
Thürnen: what changes, what does not
Working with a fiduciary from Thürnen no longer depends on geography: the documents of a business in Thürnen are shared online, while the canton Basel-Country keeps its own deadlines for the tax return.
Thürnen requires no special bookkeeping: the Code of Obligations applies at postal code 4441 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
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 Thürnen can therefore archive fully digitally.
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 Thürnen too.
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 Thürnen as anywhere.
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 Thürnen as anywhere.
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