
Accounting software deadlines in Lengwil explained simply
Accounting software deadlines in Lengwil rests on three pillars: federal law that applies across Switzerland, cantonal deadlines worth knowing, and tools that eliminate re-keying. This guide puts it all in order, fact by fact.
Digitalising accounting software: 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.
The selection criterion for a tool is not the length of its feature list but the robustness of the daily flow: reliable bank imports, VAT computed correctly (8.1 / 2.6 / 3.8%), a complete audit trail from document to entry, and a clean export for the auditor or fiduciary. Everything else is secondary.
QR-bills and friction-free collections
Instalments and partial payments are handled cleanly with distinct references per tranche: each collection finds its share, and the remaining balance stays correct at all times.
For accounting software, the share of collections matched automatically is a metric worth watching: when it drops, it is almost always a matter of misused references.
The Swiss legal frame for accounting software
AHV audits and VAT audits follow the same logic: start from the documents, trace to the entries, check consistency. A business in Lengwil with a clean audit trail sails through these exercises.
Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For accounting software, 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.

Outsource accounting software or keep it in-house?
Splitting roles clearly avoids duplication: the company captures documents and approves payments; the fiduciary checks postings, closes the year and defends the file before the authorities. Each side does what it does best — and nobody keys the same invoice twice.
In Lengwil, as everywhere, the right collaboration rhythm follows the activity: monthly for payroll and data entry, quarterly for VAT, yearly for the closing and tax advice.
Lengwil: what changes, what does not
Sole proprietorship, Sàrl or SA in Lengwil: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Thurgau.
Federal deadlines do not move in Lengwil: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 8574 changes nothing about those rules, only the sender's address.
Frequently asked questions
Do you need a fiduciary for accounting software, 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 Lengwil.
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 Lengwil as everywhere 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 Lengwil as anywhere.
What are the legal obligations for accounting software 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 Lengwil: federal law applies.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates accounting software for businesses in Lengwil: 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.