Advisor handing a document and pen to a client

Bookkeeping for engineering firms in Solothurn explained simply

Bookkeeping for engineering firms in Solothurn 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.

Late books show from the outside: poorly calibrated tax instalments, provisional filings, slow answers to the bank. Staying current is also a matter of image.

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.

For bookkeeping, a few well-chosen analytical accounts (by activity, by site) beat a forest of sub-accounts nobody ever reads.

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.

An SME in Solothurn that digitalises gains owner time first: less filing, fewer “where is that receipt?” questions, more attention to the trade — that is the real return of bookkeeping.

Two people reviewing numerical reports

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.

Solothurn: what changes, what does not

Solothurn (postal code 4500, canton Solothurn) applies the same federal rules as the rest of the country: what changes in Solothurn are the cantonal counterparts — tax administration, compensation office, commercial register.

Federal deadlines do not move in Solothurn: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 4500 changes nothing about those rules, only the sender's address.

Frequently asked questions

When must a business register for VAT?

As soon as its worldwide annual turnover reaches CHF 100,000 (CHF 250,000 for non-profit sports or cultural associations). Below that, voluntary registration remains possible and often makes sense to reclaim input VAT on investments. The threshold is federal: it applies in Solothurn as everywhere in Switzerland.

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 Solothurn: the CO dictates it, not the commune.

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.

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 Solothurn: federal law applies.

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Switch to accounting that keeps itself up to date

MyFiducia.ai automates bookkeeping for businesses in Solothurn: 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.

    Bookkeeping for engineering firms in Solothurn — Swiss guide