
Annual closing for construction companies in Oberlunkhofen: rules, deadlines, best practice
Annual closing for construction companies in Oberlunkhofen raises the same questions for most Swiss SME owners: which obligations apply, which deadlines are running, which documents to prepare. This page covers the federal rules in force — without unnecessary jargon.
Year-end closing: how the mechanics work
The CO's accounting principles frame the closing: regularity, prudence and consistency of presentation (art. 958c CO), on the going-concern assumption (art. 958a CO). In practice, that means valuation methods kept constant from one year to the next — and documented whenever they change.
For annual closing, a closing checklist reused every year transforms the exercise: same steps, same checks, same documents — only the year changes.
A Swiss SME's accounting calendar
January: salary declaration to the compensation office and salary certificates. End of February, May, August, November: quarterly VAT returns (effective method), each to be filed and paid within 60 days after the quarter ends. Within six months of year-end: approved annual accounts. Then: the tax return under cantonal deadlines, with extensions possible.
For annual closing, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
The Swiss legal frame for annual closing
For an owner in Oberlunkhofen, the question is never “do we need accounts?” but “at what level of detail?”. The CO sets the floor; the bank, the tax office and the shareholders set the rest.
The good news: the Swiss frame is stable and predictable. Structure annual closing once — chart of accounts, document flow, calendar — and the same organisation pays off for years.

A well-structured SME chart of accounts
A chart of accounts gets documented: one description line per account (what, when, VAT) is enough for two people to post the same way. It is the quality manual of annual closing, valid in Oberlunkhofen as anywhere.
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.
Oberlunkhofen: what changes, what does not
Working with a fiduciary from Oberlunkhofen no longer depends on geography: the documents of a business in Oberlunkhofen are shared online, while the canton Aargau keeps its own deadlines for the tax return.
For a business in Oberlunkhofen, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Aargau.
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 Oberlunkhofen, 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 Oberlunkhofen 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 Oberlunkhofen as anywhere.
What are the legal obligations for annual closing in Switzerland?
The foundation is the Code of Obligations: proper bookkeeping (art. 957a CO), annual accounts (balance sheet, income statement, notes) and 10-year retention of books and records (art. 958f CO). VAT applies from CHF 100,000 of turnover, and social insurance settlements from the first employee. Nothing is different in Oberlunkhofen: federal law applies.
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Switch to accounting that keeps itself up to date
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