
Tax advisory for engineering firms in La Sonnaz explained simply
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on tax advisory in La Sonnaz: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for tax advisory
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 La Sonnaz.
Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For tax advisory, that means in practice: no movement without a receipt, and an audit trail that can be reconstructed at any time — including during a VAT or AHV inspection.
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.
A company in La Sonnaz that presents clean, punctual annual accounts gains credibility — with its bank, its suppliers and the tax administration.
A Swiss SME's accounting calendar
The typical annual cycle: monthly or quarterly AHV instalments, VAT returns (quarterly under the effective method, semi-annual under the net tax rate), the final salary declaration in January, closing in the first half-year, then the tax return and the annual VAT reconciliation. Each link depends on the quality of the previous one.
For tax advisory, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.

Swiss VAT: rates, threshold and filings
A VAT return is prepared, not endured: clean VAT accounts, one code per rate and a monthly variance check make the deadline trivial — for registered businesses in La Sonnaz too.
Input VAT deduction is the flip side of VAT charged: tax paid on purchases and investments comes back through the return, receipt in hand. Rigorous entry of supplier invoices therefore translates directly into cash.
La Sonnaz: what changes, what does not
Working with a fiduciary from La Sonnaz no longer depends on geography: the documents of a business in La Sonnaz are shared online, while the canton Fribourg keeps its own deadlines for the tax return.
Federal deadlines do not move in La Sonnaz: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 1782 changes nothing about those rules, only the sender's address.
Frequently asked questions
How long must records related to tax advisory 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 La Sonnaz can therefore archive fully digitally.
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 La Sonnaz as anywhere.
Does MyFiducia.ai work for a business based in La Sonnaz?
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 La Sonnaz manages its documents, VAT and exports exactly as anywhere in Switzerland.
What are the current Swiss VAT rates?
Since 1 January 2024: 8.1% (standard), 2.6% (reduced — for example food and medicines) and 3.8% (accommodation). Returns must be filed and paid within 60 days after the period ends (quarterly under the effective method, semi-annually under the net tax rate method). These federal rates apply unchanged in La Sonnaz.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates tax advisory for businesses in La Sonnaz: 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.