
Social security contributions in Switzerland in Aristau: the practical guide
Delegate, digitalise or do it all yourself? Around social security contributions in Aristau, every SME draws its own line. The reference points below — federal law, cantonal practice and lessons from the field — help you place the cursor well.
The Swiss legal frame for social security contributions
Whether a business sits in Aristau or elsewhere in Switzerland, the same federal law applies — one of the strengths of the Swiss system for social security contributions. Cantonal differences concentrate on taxation (rates, filing deadlines); bookkeeping itself follows art. 957 ff. CO everywhere.
The good news: the Swiss frame is stable and predictable. Structure social security contributions once — chart of accounts, document flow, calendar — and the same organisation pays off for years.
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.
Migrate in stages: supplier invoices first (high volume, immediate gain), then receivables with the QR-bill, finally payroll and the closing. At each stage, comparing one month before/after is enough to prove the gain — no theoretical promises needed.
Outsource social security contributions or keep it in-house?
A fiduciary's cost depends first on the quality of the data received: digitised, filed, reconciled documents are processed fast; a box of loose receipts is billed by the hour. Improving the internal preparation of social security contributions lowers fees more surely than any negotiation.
Three signals say it is time to delegate more: missed deadlines (VAT, AHV), entries running months behind, or an owner spending evenings on receipts instead of the business. Conversely, an SME equipped with modern software can safely take day-to-day entry back in-house.

A Swiss SME's accounting calendar
Extensions exist and can be requested: cantonal deadlines for the tax return, deferral of the VAT filing on a reasoned request. But an extension does not stop interest: on VAT, default interest runs from the ordinary due date even when more time has been granted.
For a business in Aristau, an isolated delay can be caught up; a structural delay is paid in interest, fines and stress. The difference between the two: a system, not good intentions.
Aristau: what changes, what does not
Aristau (postal code 5628, canton Aargau) applies the same federal rules as the rest of the country: what changes in Aristau are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Aristau: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5628 changes nothing about those rules, only the sender's address.
Frequently asked questions
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 Aristau.
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 Aristau.
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.
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 Aristau as anywhere.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates social security contributions for businesses in Aristau: 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.