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Everything that matters about bookkeeping for construction companies in Onex

Bookkeeping for construction companies in Onex rests on three pillars: federal law that applies across Switzerland, cantonal deadlines worth knowing, and tools that eliminate re-keying. This guide puts it all in order, fact by fact.

The Swiss legal frame for bookkeeping

Whether a business sits in Onex or elsewhere in Switzerland, the same federal law applies — one of the strengths of the Swiss system for bookkeeping. Cantonal differences concentrate on taxation (rates, filing deadlines); bookkeeping itself follows art. 957 ff. CO everywhere.

For bookkeeping, 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.

Digitalising bookkeeping: what actually works

Digitising does not mean hoarding PDFs: without the document-entry link, a digital file is as opaque as a box of archives — true in Onex as everywhere.

Electronic archiving is fully recognised: Swiss bookkeeping regulation admits electronic retention of records provided integrity and readability are guaranteed for the 10 years of art. 958f CO. A paper binder is no longer an obligation — provided the archiving system is serious.

A Swiss SME's accounting calendar

An accounting calendar only lives if it is shared: owner, in-house bookkeeper and fiduciary must see the same deadlines and the same status — the rule holds for every SME in Onex.

The useful reflex: date every obligation the moment it arises. An employee hired means AHV/LPP deadlines created; VAT registration means a filing cycle set; a closing date fixed means backward planning of the close. Well organised, the bookkeeping calendar fills itself.

Smiling advisor with a headset at their workstation

A well-structured SME chart of accounts

The test of a good chart of accounts is a single question: can the owner find the margins in three clicks? If not, the chart serves the tax office but not the business — even in Onex.

For bookkeeping, a few well-chosen analytical accounts (by activity, by site) beat a forest of sub-accounts nobody ever reads.

Onex: what changes, what does not

Sole proprietorship, Sàrl or SA in Onex: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Geneva.

Onex requires no special bookkeeping: the Code of Obligations applies at postal code 1213 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.

Frequently asked questions

What are the legal obligations for bookkeeping 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 Onex: federal law applies.

What is simplified bookkeeping and who can use it?

Sole proprietorships and partnerships under CHF 500,000 of revenue may limit themselves to recording income, expenses and assets (art. 957 para. 2 CO). Once over the threshold — or upon founding a Sàrl or an SA — full accounts with balance sheet, income statement and notes become mandatory. The CHF 500,000 threshold is assessed the same way in Onex.

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 Onex as everywhere in Switzerland.

Does MyFiducia.ai work for a business based in Onex?

Yes: the platform runs online, the rules applied are federal (VAT, CO, AHV), and the file can be shared with any fiduciary. A business in Onex manages its documents, VAT and exports exactly as anywhere in Switzerland.

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Switch to accounting that keeps itself up to date

MyFiducia.ai automates bookkeeping for businesses in Onex: 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.