
Bookkeeping for engineering firms in Basel explained simply
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on bookkeeping in Basel: what the law requires, what can be automated, and when to delegate.
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 Basel too.
The annual accounts (art. 958 CO) consist of the balance sheet, the income statement and the notes; they must be drawn up within six months of the year-end so the general meeting can approve them. A delay here cascades into the tax return and the final social insurance settlements.
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?
The Swiss fiduciary market is dense and governed by professional practice: industry standards, business secrecy, civil liability. Compare offers on three concrete criteria — exact scope (data entry? closing? payroll? VAT?), a named contact person, and the tools used. It prevents year-end misunderstandings.
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
Extensions exist and can be requested: cantonal deadlines for the tax return, deferral of the VAT filing on a reasoned request. But an extension does not stop interest: on VAT, default interest runs from the ordinary due date even when more time has been granted.
For bookkeeping, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
Basel: what changes, what does not
Sole proprietorship, Sàrl or SA in Basel: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Basel-City.
Federal deadlines do not move in Basel: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 4001 changes nothing about those rules, only the sender's address.
Frequently asked questions
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 Basel 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 Basel: federal law applies.
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 Basel.
Which social contributions does a Swiss employer pay?
AHV/IV/APG: 5.3% employer share (the same is withheld from the employee); unemployment insurance: 1.1% each up to CHF 148,200 a year; occupational pension (LPP) by age and plan (employer at least 50%); occupational accident insurance paid by the employer; family allowances by canton. For an employer in Basel, family allowances follow the canton's rates.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates bookkeeping for businesses in Basel: AI-read documents, posting suggestions, VAT and exports ready for your fiduciary. Try the platform or browse our other guides.
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