
Social security contributions for engineering firms in Wiliberg: 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 Wiliberg: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for social security contributions
Swiss accounting law has been unified in the Code of Obligations since 2013: the same bookkeeping rules (art. 957a CO) and retention rules (art. 958f CO — 10 years for books, vouchers and reports) apply regardless of legal form. Social security contributions sits squarely within this frame, including for companies based in Wiliberg.
Late books show from the outside: poorly calibrated tax instalments, provisional filings, slow answers to the bank. Staying current is also a matter of image.
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.
Digitalising social security contributions: what actually works
Access for the fiduciary, the auditor and employees is set by roles: view, enter, approve, close. Well-set rights protect the data and speed up collaboration.
An SME in Wiliberg that digitalises gains owner time first: less filing, fewer “where is that receipt?” questions, more attention to the trade — that is the real return of social security contributions.

Outsource social security contributions or keep it in-house?
Splitting roles clearly avoids duplication: the company captures documents and approves payments; the fiduciary checks postings, closes the year and defends the file before the authorities. Each side does what it does best — and nobody keys the same invoice twice.
A business in Wiliberg can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — social security contributions splits very well.
Wiliberg: what changes, what does not
Wiliberg (postal code 5058, canton Aargau) applies the same federal rules as the rest of the country: what changes in Wiliberg are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Wiliberg: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5058 changes nothing about those rules, only the sender's address.
Frequently asked questions
What is the difference between a limited and an ordinary audit?
The ordinary audit applies to companies exceeding, for two consecutive years, two of three thresholds: CHF 20 million balance sheet total, CHF 40 million revenue, 250 full-time positions. Others fall under the limited audit, and those with no more than ten full-time positions on annual average can opt out with all shareholders' consent. These federal thresholds do not depend on the registered seat — in Wiliberg as anywhere.
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 Wiliberg.
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 Wiliberg as everywhere in Switzerland.
How long must records related to social security contributions 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 Wiliberg can therefore archive fully digitally.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates social security contributions for businesses in Wiliberg: 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.