
Payroll administration for engineering firms in Trélex explained simply
Delegate, digitalise or do it all yourself? Around payroll administration in Trélex, 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.
The Swiss legal frame for payroll administration
Responsibility for the books is personal: in an SA, organising the accounting is one of the board's non-transferable duties (art. 716a CO); in a Sàrl, the managing directors carry the same duty. Outsourcing the execution never transfers that underlying responsibility, including for a company based in Trélex.
Also worth knowing: accounts may be drawn up in the currency most relevant to the business; if that is not the franc, values must additionally be stated in CHF (art. 958d para. 3 CO). Internationally active companies gain books that match their economic reality.
Digitalising payroll administration: 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 Trélex 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.
Outsource payroll administration or keep it in-house?
The Swiss fiduciary market is dense and governed by professional practice: industry standards, business secrecy, civil liability. Compare offers on three concrete criteria — exact scope (data entry? closing? payroll? VAT?), a named contact person, and the tools used. It prevents year-end misunderstandings.
For payroll administration, a quarterly 30-minute check-in with the fiduciary beats an annual marathon: questions get handled while they are small.

A Swiss SME's accounting calendar
Three families of deadlines shape the year: federal (VAT within 60 days, salary declaration in January), cantonal (tax return, extensions depending on the canton, including in Trélex) and internal (closing, general meeting within six months). Mixing them up is the leading cause of delays.
For payroll administration, two dates lock themselves in every year: the January salary declaration and the general meeting within six months — everything else is planned around them.
Trélex: what changes, what does not
Working with a fiduciary from Trélex no longer depends on geography: the documents of a business in Trélex are shared online, while the canton Vaud keeps its own deadlines for the tax return.
For a business in Trélex, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Vaud.
Frequently asked questions
Does MyFiducia.ai work for a business based in Trélex?
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 Trélex manages its documents, VAT and exports exactly as anywhere in Switzerland.
Can payroll administration be automated with AI?
Largely, yes: automatic document reading, posting suggestions, bank reconciliation via QR references and VAT exports. Human approval remains essential — AI prepares, the professional checks. That is exactly how MyFiducia.ai approaches payroll administration.
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 Trélex, family allowances follow the canton's rates.
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 Trélex as anywhere.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates payroll administration for businesses in Trélex: 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.