Bookkeeping for masonry contractors in Lengnau (AG): the practical guide
Whether you run a Sàrl, an SA or a sole proprietorship in Lengnau (AG), bookkeeping eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
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 Lengnau (AG).
The good news: the Swiss frame is stable and predictable. Structure bookkeeping once — chart of accounts, document flow, calendar — and the same organisation pays off for years.
A Swiss SME's accounting calendar
January: salary declaration to the compensation office and salary certificates. End of February, May, August, November: quarterly VAT returns (effective method), each to be filed and paid within 60 days after the quarter ends. Within six months of year-end: approved annual accounts. Then: the tax return under cantonal deadlines, with extensions possible.
The useful reflex: date every obligation the moment it arises. An employee hired means AHV/LPP deadlines created; VAT registration means a filing cycle set; a closing date fixed means backward planning of the close. Well organised, the bookkeeping calendar fills itself.
A well-structured SME chart of accounts
A chart of accounts gets documented: one description line per account (what, when, VAT) is enough for two people to post the same way. It is the quality manual of bookkeeping, valid in Lengnau (AG) as anywhere.
For a business in Lengnau (AG), the Sterchi/Käfer structure also eases benchmarking: banks and fiduciaries reason on those standard classes to situate an SME's bookkeeping.
Digitalising bookkeeping: what actually works
Artificial intelligence has changed the economics of bookkeeping: automatic invoice reading reaches recognition rates that make manual entry marginal, and posting suggestions learn from corrections. The accountant does not disappear — the job shifts from data entry to control and advice.
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.
Lengnau (AG): what changes, what does not
Lengnau (AG) (postal code 5426, canton Aargau) applies the same federal rules as the rest of the country: what changes in Lengnau (AG) are the cantonal counterparts — tax administration, compensation office, commercial register.
Lengnau (AG) requires no special bookkeeping: the Code of Obligations applies at postal code 5426 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
Does MyFiducia.ai work for a business based in Lengnau (AG)?
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 Lengnau (AG) manages its documents, VAT and exports exactly as anywhere in Switzerland.
What is the difference between a limited and an ordinary audit?
The ordinary audit applies to companies exceeding, for two consecutive years, two of three thresholds: CHF 20 million balance sheet total, CHF 40 million revenue, 250 full-time positions. Others fall under the limited audit, and those with no more than ten full-time positions on annual average can opt out with all shareholders' consent. These federal thresholds do not depend on the registered seat — in Lengnau (AG) 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 Lengnau (AG): federal law applies.
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 Lengnau (AG), family allowances follow the canton's rates.
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Switch to accounting that keeps itself up to date
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