
Bookkeeping for plumbers in Mellingen: the practical guide
Whether you run a Sàrl, an SA or a sole proprietorship in Mellingen, 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
Three documents summarise the health of a Swiss business: the balance sheet (what it owns), the income statement (what it earns) and the notes (what else you should know). All the work of bookkeeping converges on those three pages, in Mellingen too.
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.
A well-structured SME chart of accounts
Nearly all Swiss SMEs rely on the standard SME chart of accounts (Sterchi/Käfer): classes 1 (assets) to 9 (closing), with revenue in class 3 and expenses in classes 4 to 6. Using this standard structure makes conversations with your fiduciary, auditor and tax administration far easier.
For bookkeeping, the right granularity is decisive: enough accounts to steer the business (margins by activity, expenses by nature), few enough that every entry finds its place without hesitation. The VAT accounts (input VAT, VAT due) deserve special care — they are the basis of the annual reconciliation.
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 Mellingen as elsewhere.
For bookkeeping, a quarterly 30-minute check-in with the fiduciary beats an annual marathon: questions get handled while they are small.
Mellingen: what changes, what does not
Mellingen (postal code 5507, canton Aargau) applies the same federal rules as the rest of the country: what changes in Mellingen are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Mellingen: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5507 changes nothing about those rules, only the sender's address.
Frequently asked questions
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.
How much does bookkeeping cost in Mellingen?
It depends on document volume, the number of salaries and VAT complexity — no serious figure can be quoted without examining the file. Two levers cut the bill everywhere: digitised, well-filed receipts and software that prepares entries instead of having them re-keyed.
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 Mellingen as anywhere.
Does MyFiducia.ai work for a business based in Mellingen?
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 Mellingen manages its documents, VAT and exports exactly as anywhere in Switzerland.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates bookkeeping for businesses in Mellingen: 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.