
Limited statutory audit for engineering firms in Zeihen: what every SME should know
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 Zeihen: 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 an SME in Zeihen, the closing is also decision time: distributions, provisions, investments to anticipate. A file ready in February leaves time to decide; one ready in June just endures.
The Swiss legal frame for limited statutory audit
A small business does not mean small obligations: from the first salary or the first VAT return, mistakes get expensive — in Zeihen as anywhere.
The good news: the Swiss frame is stable and predictable. Structure limited statutory audit once — chart of accounts, document flow, calendar — and the same organisation pays off for years.
A well-structured SME chart of accounts
Shareholder current accounts demand strict hygiene: every private withdrawal documented, interest at the rates accepted by the tax administration, and a clean-up at closing.
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.

A Swiss SME's accounting calendar
The professionals' trick: handle every deadline at D-30, not D-1. A VAT return prepared a month early leaves time to chase a missing document without penalty.
For limited statutory audit, deadline discipline is worth real money: default interest on late VAT, AHV adjustments, tax fines. A shared deadline calendar — fed by up-to-date figures — remains the simplest safeguard.
Zeihen: what changes, what does not
Sole proprietorship, Sàrl or SA in Zeihen: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Aargau.
Federal deadlines do not move in Zeihen: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5079 changes nothing about those rules, only the sender's address.
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 Zeihen can therefore archive fully digitally.
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 Zeihen as anywhere.
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 Zeihen as everywhere in Switzerland.
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 Zeihen as anywhere.
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