
Social security contributions required documents in Lonay: the practical guide
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on social security contributions in Lonay: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for social security contributions
AHV audits and VAT audits follow the same logic: start from the documents, trace to the entries, check consistency. A business in Lonay with a clean audit trail sails through these exercises.
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 social security contributions run entirely on digital tools — no paper binder is required.
Salaries and social contributions: the rates to know
Every salary paid in Switzerland triggers joint contributions: AHV/IV/APG at 10.6% in total, i.e. 5.3% borne by the employer and 5.3% withheld from the employee; unemployment insurance at 2.2% (1.1% each) up to CHF 148,200 of annual salary. Add occupational pension (LPP credits of 7 to 18% of the coordinated salary depending on age, employer at least 50%), accident insurance (occupational accidents paid by the employer) and family allowances.
For social security contributions, the practical challenge is the calendar: AHV instalments during the year, salary declaration to the compensation office in January, salary certificates for staff, and final LPP/accident settlements. A clean payroll base avoids unpleasant catch-up invoices.
A Swiss SME's accounting calendar
Tax instalments are steered: too low, they set up a salty final bill; too high, they tie up cash. Adjusting them on current figures is a profitable reflex, in Lonay as anywhere.
For social security contributions, two dates lock themselves in every year: the January salary declaration and the general meeting within six months — everything else is planned around them.

Digitalising social security contributions: what actually works
A serious accounting document archive links every record to its entry, timestamps versions and logs access — exactly what Swiss bookkeeping regulation expects from probative electronic retention. Chronological filing by financial year becomes an automatic by-product.
For social security contributions, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
Lonay: what changes, what does not
Sole proprietorship, Sàrl or SA in Lonay: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Vaud.
Lonay requires no special bookkeeping: the Code of Obligations applies at postal code 1027 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
Do you need a fiduciary for social security contributions, 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 Lonay.
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 Lonay.
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 Lonay too.
Can social security contributions 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 social security contributions.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates social security contributions for businesses in Lonay: 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.