
Bookkeeping for engineering firms in Lonay: what every SME should know
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on bookkeeping in Lonay: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for bookkeeping
For an owner in Lonay, the question is never “do we need accounts?” but “at what level of detail?”. The CO sets the floor; the bank, the tax office and the shareholders set the rest.
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
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.
Outsource bookkeeping or keep it in-house?
Outsourcing does not exempt you from understanding: an owner who can read the balance sheet and the income statement challenges the fiduciary better — and pays for advice, not re-keying.
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
An accounting calendar only lives if it is shared: owner, in-house bookkeeper and fiduciary must see the same deadlines and the same status — the rule holds for every SME in Lonay.
For bookkeeping, deadline discipline is worth real money: default interest on late VAT, AHV adjustments, tax fines. A shared deadline calendar — fed by up-to-date figures — remains the simplest safeguard.
Lonay: what changes, what does not
Lonay (postal code 1027, canton Vaud) applies the same federal rules as the rest of the country: what changes in Lonay are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Lonay: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 1027 changes nothing about those rules, only the sender's address.
Frequently asked questions
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 Lonay as anywhere.
What are the legal obligations for bookkeeping 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 Lonay: federal law applies.
How much does bookkeeping cost in Lonay?
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.
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 Lonay: the CO dictates it, not the commune.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates bookkeeping for businesses in Lonay: 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.