Tax advisory for startups in Sion: rules, deadlines, best practice
Whether you run a Sàrl, an SA or a sole proprietorship in Sion, tax advisory eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
The Swiss legal frame for tax advisory
A small business does not mean small obligations: from the first salary or the first VAT return, mistakes get expensive — in Sion as anywhere.
The law also settles the form: accounts may be kept in a national language or in English, on paper or electronically (art. 957a para. 5 CO). That pragmatism lets tax advisory run entirely on digital tools — no paper binder is required.
Swiss VAT: rates, threshold and filings
Exports, services abroad, acquisition tax: as soon as anything international enters the picture, VAT gets demanding (place of supply, acquisition tax on services). Better to set the rules once with a professional than to correct three financial years.
A business in Sion that crosses the threshold mid-year must register without delay: retroactive registration with interest always costs more than signing up on time.
Year-end closing: how the mechanics work
Companies exceeding two of three thresholds for two consecutive years — CHF 20 million balance sheet total, CHF 40 million revenue, 250 full-time positions — move to an ordinary audit. Below that, the limited audit applies, and companies with no more than ten full-time positions on annual average can opt out with the consent of all shareholders.
For tax advisory, the golden rule is to discover nothing in January: every uncertainty (doubtful receivable, dispute, unsellable stock) must be identified before the closing date, not after.
Outsource tax advisory or keep it in-house?
Outsourcing tax advisory to a fiduciary frees up time and secures compliance; keeping it in-house preserves a continuous view and costs less in fees. The best answer is often hybrid: the company captures and digitises as it goes, the fiduciary supervises, closes the books and represents the company before the authorities.
For tax advisory, the internal-external duo works when both sides see the same file: same entries, same documents, same deadlines. Misunderstandings are born from parallel copies.
Sion: what changes, what does not
Sole proprietorship, Sàrl or SA in Sion: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Valais.
Sion requires no special bookkeeping: the Code of Obligations applies at postal code 1950 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
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 Sion, family allowances follow the canton's rates.
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 Sion as everywhere in Switzerland.
Do you need a fiduciary for tax advisory, or can you do it yourself?
Both are defensible. Below CHF 500,000 of revenue, a sole proprietorship may keep simplified accounts itself. As soon as payroll, VAT and a closing with tax stakes are involved, professional support prevents mistakes that cost more than the fees. With a shared platform, the fiduciary does not even need to be in Sion.
What are the legal obligations for tax advisory 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 Sion: federal law applies.
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