
Everything that matters about accounting outsourcing automation in Lenzburg
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 Lenzburg.
The Swiss legal frame for accounting outsourcing
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. Accounting outsourcing sits squarely within this frame, including for companies based in Lenzburg.
Also worth knowing: accounts may be drawn up in the currency most relevant to the business; if that is not the franc, values must additionally be stated in CHF (art. 958d para. 3 CO). Internationally active companies gain books that match their economic reality.
Outsource accounting outsourcing or keep it in-house?
A good test before choosing: ask the fiduciary HOW it wants to receive the documents. A precise answer (formats, frequency, platform) says more than any brochure — including in Lenzburg.
For accounting outsourcing, the internal-external duo works when both sides see the same file: same entries, same documents, same deadlines. Misunderstandings are born from parallel copies.
Year-end closing: how the mechanics work
The closing turns day-to-day bookkeeping into annual accounts: balance sheet, income statement and notes (art. 958 CO). Mandatory stops: accruals and deferrals, depreciation, commercially justified provisions, inventory of stock and work in progress, then VAT and AHV reconciliations.
For accounting outsourcing, a closing checklist reused every year transforms the exercise: same steps, same checks, same documents — only the year changes.

Digitalising accounting outsourcing: what actually works
Digitising does not mean hoarding PDFs: without the document-entry link, a digital file is as opaque as a box of archives — true in Lenzburg as everywhere.
The winning pair for accounting outsourcing: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.
Lenzburg: what changes, what does not
Working with a fiduciary from Lenzburg no longer depends on geography: the documents of a business in Lenzburg are shared online, while the canton Aargau keeps its own deadlines for the tax return.
Federal deadlines do not move in Lenzburg: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5600 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 Lenzburg.
What are the legal obligations for accounting outsourcing 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 Lenzburg: federal law applies.
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 Lenzburg too.
Do you need a fiduciary for accounting outsourcing, 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 Lenzburg.
Also worth reading
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates accounting outsourcing for businesses in Lenzburg: 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.