
Bookkeeping for construction companies in Wettingen: what every SME should know
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on bookkeeping in Wettingen: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for bookkeeping
For an owner in Wettingen, the question is never “do we need accounts?” but “at what level of detail?”. The CO sets the floor; the bank, the tax office and the shareholders set the rest.
One simple principle drives bookkeeping: every franc in or out must be explainable by a document, an entry and an account. All of Swiss accounting law fits inside that traceability requirement.
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 bookkeeping, deadline discipline is worth real money: default interest on late VAT, AHV adjustments, tax fines. A shared deadline calendar — fed by up-to-date figures — remains the simplest safeguard.
Digitalising bookkeeping: 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.
Electronic archiving is fully recognised: Swiss bookkeeping regulation admits electronic retention of records provided integrity and readability are guaranteed for the 10 years of art. 958f CO. A paper binder is no longer an obligation — provided the archiving system is serious.

Outsource bookkeeping or keep it in-house?
Outsourcing does not exempt you from understanding: an owner who can read the balance sheet and the income statement challenges the fiduciary better — and pays for advice, not re-keying.
A business in Wettingen can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — bookkeeping splits very well.
Wettingen: what changes, what does not
Sole proprietorship, Sàrl or SA in Wettingen: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Aargau.
For a business in Wettingen, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Aargau.
Frequently asked questions
What are the legal obligations for bookkeeping 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 Wettingen: federal law applies.
Effective VAT method or net tax rate: how to choose?
The effective method deducts actual input VAT and files quarterly; the net tax rate method applies a flat industry rate to turnover, semi-annually, with no separate input VAT deduction. The flat rate suits low-cost structures; as investments grow, the effective method usually wins again. The choice rests on the company's own figures, in Wettingen as anywhere.
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 Wettingen.
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 Wettingen as everywhere in Switzerland.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates bookkeeping for businesses in Wettingen: 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.