
Social security contributions for architecture firms in Willisau: rules, deadlines, best practice
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 Willisau: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for social security contributions
In Switzerland, the duty to keep accounts stems from art. 957 ff. of the Code of Obligations. Legal entities (Sàrl, SA) and sole proprietorships with at least CHF 500,000 in revenue keep full accounts: balance sheet, income statement and notes. Below that threshold, a simplified record of income, expenses and assets is sufficient.
The annual accounts (art. 958 CO) consist of the balance sheet, the income statement and the notes; they must be drawn up within six months of the year-end so the general meeting can approve them. A delay here cascades into the tax return and the final social insurance settlements.
Digitalising social security contributions: what actually works
The classic digitalisation traps are avoidable: scanning without quality control (unreadable records), stacking disconnected tools (double entry in disguise), or neglecting access rights. One single flow from document to entry, with clear roles, beats five shiny apps.
The selection criterion for a tool is not the length of its feature list but the robustness of the daily flow: reliable bank imports, VAT computed correctly (8.1 / 2.6 / 3.8%), a complete audit trail from document to entry, and a clean export for the auditor or fiduciary. Everything else is secondary.
Outsource social security contributions or keep it in-house?
The scope goes down in writing: who enters data, who approves payments, who answers the tax office, who keeps the originals. Every “we'll see” at the start becomes a December misunderstanding — in Willisau as elsewhere.
A business in Willisau can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — social security contributions splits very well.

A Swiss SME's accounting calendar
Every deadline has an owner: an obligation “of everyone” is kept by no one. Naming one person per deadline family (VAT, payroll, taxes) closes the gaps.
For social security contributions, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
Willisau: what changes, what does not
Sole proprietorship, Sàrl or SA in Willisau: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Lucerne.
Federal deadlines do not move in Willisau: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 6126 changes nothing about those rules, only the sender's address.
Frequently asked questions
What are the legal obligations for social security contributions 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 Willisau: federal law applies.
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 Willisau as everywhere in Switzerland.
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 Willisau, family allowances follow the canton's rates.
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 Willisau.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates social security contributions for businesses in Willisau: 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.