Bookkeeping for SA companies in Seon: the practical guide
Swiss accounting law (art. 957 ff. of the Code of Obligations) sets a precise frame, yet day-to-day practice often stays fuzzy. This guide walks through what actually matters for a business based in Seon.
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 Seon.
The good news: the Swiss frame is stable and predictable. Structure bookkeeping once — chart of accounts, document flow, calendar — and the same organisation pays off for years.
A Swiss SME's accounting calendar
Three families of deadlines shape the year: federal (VAT within 60 days, salary declaration in January), cantonal (tax return, extensions depending on the canton, including in Seon) and internal (closing, general meeting within six months). Mixing them up is the leading cause of delays.
For bookkeeping, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
Digitalising bookkeeping: what actually works
Security is part of digitalisation: named access, tested backups, encryption of sensitive data. A digital accounting file is protected like a safe — because it is one.
For bookkeeping, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
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 Seon as elsewhere.
A business in Seon can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — bookkeeping splits very well.
Seon: what changes, what does not
Seon (postal code 5703, canton Aargau) applies the same federal rules as the rest of the country: what changes in Seon are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Seon: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5703 changes nothing about those rules, only the sender's address.
Frequently asked questions
Which documents should be prepared for the year-end closing?
Bank and cash statements at the closing date, the inventory of stock and work in progress, final AHV/LPP/accident settlements, contracts signed or amended during the year, invoices straddling two years and the detail of accruals. With an up-to-date document archive, most of it is already there. The list is identical in Seon: the CO dictates it, not the commune.
What are the current Swiss VAT rates?
Since 1 January 2024: 8.1% (standard), 2.6% (reduced — for example food and medicines) and 3.8% (accommodation). Returns must be filed and paid within 60 days after the period ends (quarterly under the effective method, semi-annually under the net tax rate method). These federal rates apply unchanged in Seon.
Do you need a fiduciary for bookkeeping, 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 Seon.
When is entry in the commercial register mandatory?
A Sàrl and an SA only come into existence with their registration. A sole proprietorship must register from CHF 100,000 of annual revenue; below that, registration stays voluntary but adds credibility and protects the business name. Registration goes through the canton's commercial register office — for Seon too.
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