
Bookkeeping for engineering firms in Wettingen explained simply
Whether you run a Sàrl, an SA or a sole proprietorship in Wettingen, bookkeeping eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
The Swiss legal frame for bookkeeping
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. Bookkeeping sits squarely within this frame, including for companies based in Wettingen.
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.
Outsource bookkeeping 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 Wettingen as elsewhere.
A clear mandate agreement states who does what by when: document handover, posting deadlines, filing calendar, and responsibility for delays. A shared platform (same data, same document archive) between the company and its fiduciary eliminates binder ping-pong and duplicate entry.
A Swiss SME's accounting calendar
The typical annual cycle: monthly or quarterly AHV instalments, VAT returns (quarterly under the effective method, semi-annual under the net tax rate), the final salary declaration in January, closing in the first half-year, then the tax return and the annual VAT reconciliation. Each link depends on the quality of the previous one.
The useful reflex: date every obligation the moment it arises. An employee hired means AHV/LPP deadlines created; VAT registration means a filing cycle set; a closing date fixed means backward planning of the close. Well organised, the bookkeeping calendar fills itself.

Digitalising bookkeeping: what actually works
Accounting digitalisation always follows the same path: capture documents at the source (photo or PDF upload), let automatic recognition extract supplier, amount, date and VAT, approve the proposed entries, then archive each document linked to its entry. Every step removes a re-keying — and therefore an error source.
For an SME in Wettingen, the real gain of digitalised bookkeeping shows day to day: no paper pile at month-end, VAT prepared continuously, and an owner reading today's figures rather than last quarter's.
Wettingen: what changes, what does not
Wettingen (postal code 5430, canton Aargau) applies the same federal rules as the rest of the country: what changes in Wettingen are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Wettingen: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5430 changes nothing about those rules, only the sender's address.
Frequently asked questions
How long must records related to bookkeeping 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 Wettingen can therefore archive fully digitally.
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 Wettingen, family allowances follow the canton's rates.
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 Wettingen as anywhere.
Does MyFiducia.ai work for a business based in Wettingen?
Yes: the platform runs online, the rules applied are federal (VAT, CO, AHV), and the file can be shared with any fiduciary. A business in Wettingen manages its documents, VAT and exports exactly as anywhere 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.