
Bookkeeping for engineering firms in Penthaz: rules, deadlines, best practice
Bookkeeping for engineering firms in Penthaz raises the same questions for most Swiss SME owners: which obligations apply, which deadlines are running, which documents to prepare. This page covers the federal rules in force — without unnecessary jargon.
The Swiss legal frame for bookkeeping
In Switzerland, the duty to keep accounts stems from art. 957 ff. of the Code of Obligations. Legal entities (Sàrl, SA) and sole proprietorships with at least CHF 500,000 in revenue keep full accounts: balance sheet, income statement and notes. Below that threshold, a simplified record of income, expenses and assets is sufficient.
For bookkeeping, the classic early mistake remains mixing private and business: a dedicated bank account and documented private withdrawals eliminate half the discussions with the tax office.
Digitalising bookkeeping: what actually works
Access for the fiduciary, the auditor and employees is set by roles: view, enter, approve, close. Well-set rights protect the data and speed up collaboration.
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?
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.
Changing fiduciary is not a drama: the accounting data belongs to the company, and a clean export (entries, chart of accounts, linked documents) allows a transition at year-end. A provider who locks in a client's data says a lot about how it works.

A well-structured SME chart of accounts
Concretely, bookkeeping benefits from three tiers: balance-sheet accounts (classes 1-2) kept spotless for the closing, income accounts (classes 3-6) shaped for steering, and closing accounts (class 9) reserved for year-end entries. Each tier has its rhythm and its owner.
In an SME in Penthaz, the chart of accounts is also a delegation tool: clear posting rules let a non-accountant prepare most entries without error.
Penthaz: what changes, what does not
Sole proprietorship, Sàrl or SA in Penthaz: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Vaud.
Federal deadlines do not move in Penthaz: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 1303 changes nothing about those rules, only the sender's address.
Frequently asked questions
Does MyFiducia.ai work for a business based in Penthaz?
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 Penthaz manages its documents, VAT and exports exactly as anywhere in Switzerland.
How long must records related to bookkeeping be kept?
Ten years from the end of the financial year concerned (art. 958f CO). Electronic retention is permitted if the integrity and readability of the records are guaranteed — a serious digital archive validly replaces paper binders. A business in Penthaz can therefore archive fully digitally.
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 Penthaz: federal law applies.
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 Penthaz: the CO dictates it, not the commune.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates bookkeeping for businesses in Penthaz: 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.