Bookkeeping for the self-employed in Mammern: rules, deadlines, best practice
Bookkeeping for the self-employed in Mammern 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
Swiss accounting law has been unified in the Code of Obligations since 2013: the same bookkeeping rules (art. 957a CO) and retention rules (art. 958f CO — 10 years for books, vouchers and reports) apply regardless of legal form. Bookkeeping sits squarely within this frame, including for companies based in Mammern.
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
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.
Standard numbering also enables automation: stable posting rules (same supplier, same account) make data entry predictable and the audit faster. Avoid changing the chart of accounts mid-year — migrate at the closing date, with a documented mapping table.
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 Mammern.
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.
Mammern: what changes, what does not
Mammern (postal code 8265, canton Thurgau) applies the same federal rules as the rest of the country: what changes in Mammern are the cantonal counterparts — tax administration, compensation office, commercial register.
Federal deadlines do not move in Mammern: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 8265 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 Mammern as anywhere.
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 Mammern, family allowances follow the canton's rates.
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 Mammern 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 Mammern: federal law applies.
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Switch to accounting that keeps itself up to date
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