
Everything that matters about bookkeeping step by step in Reinach (AG)
Whether you run a Sàrl, an SA or a sole proprietorship in Reinach (AG), 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
A small business does not mean small obligations: from the first salary or the first VAT return, mistakes get expensive — in Reinach (AG) as anywhere.
Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For bookkeeping, that means in practice: no movement without a receipt, and an audit trail that can be reconstructed at any time — including during a VAT or AHV inspection.
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 Reinach (AG) as elsewhere.
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 well-structured SME chart of accounts
A good chart of accounts tells the story of the business: classes 1 and 2 describe what it owns and owes, class 3 what it sells, classes 4 to 6 what it consumes. Private accounts (sole proprietorships) and shareholder current accounts (Sàrl/SA) must stay spotless: they are the first thing examined in a tax audit.
Suspense accounts (to clarify) are useful provided they are emptied monthly: a swelling “miscellaneous” account is the classic symptom of a chart that no longer fits the activity.

Digitalising bookkeeping: 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 Reinach (AG) as everywhere.
The winning pair for bookkeeping: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.
Reinach (AG): what changes, what does not
Sole proprietorship, Sàrl or SA in Reinach (AG): the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Aargau.
Federal deadlines do not move in Reinach (AG): VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5734 changes nothing about those rules, only the sender's address.
Frequently asked questions
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 Reinach (AG).
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 Reinach (AG).
Can bookkeeping 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 bookkeeping.
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 Reinach (AG) as anywhere.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates bookkeeping for businesses in Reinach (AG): 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.