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Accounting software for opticians in Lengnau (AG): what every SME should know

Whether you run a Sàrl, an SA or a sole proprietorship in Lengnau (AG), accounting software eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.

Digitalising accounting software: what actually works

Digitising does not mean hoarding PDFs: without the document-entry link, a digital file is as opaque as a box of archives — true in Lengnau (AG) as everywhere.

The winning pair for accounting software: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.

Outsource accounting software 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.

For accounting software, the internal-external duo works when both sides see the same file: same entries, same documents, same deadlines. Misunderstandings are born from parallel copies.

QR-bills and friction-free collections

Technically, two routes coexist: the classic IBAN with an optional reference, or the QR-IBAN which requires a structured 27-position QR reference. Only the second route makes matching truly automatic — every payment carries the exact identifier of its invoice.

For accounting software, invoicing fast changes everything: a service billed the week it is delivered gets paid noticeably earlier than a month-end batch invoice.

Pen pointing at a bar chart on paper

The Swiss legal frame for accounting software

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.

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.

Lengnau (AG): what changes, what does not

Working with a fiduciary from Lengnau (AG) no longer depends on geography: the documents of a business in Lengnau (AG) are shared online, while the canton Aargau keeps its own deadlines for the tax return.

Federal deadlines do not move in Lengnau (AG): VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5426 changes nothing about those rules, only the sender's address.

Frequently asked questions

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.

How long must records related to accounting software 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 Lengnau (AG) can therefore archive fully digitally.

When is entry in the commercial register mandatory?

A Sàrl and an SA only come into existence with their registration. A sole proprietorship must register from CHF 100,000 of annual revenue; below that, registration stays voluntary but adds credibility and protects the business name. Registration goes through the canton's commercial register office — for Lengnau (AG) too.

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 Lengnau (AG).

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Switch to accounting that keeps itself up to date

MyFiducia.ai automates accounting software for businesses in Lengnau (AG): 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.

    Accounting software for opticians in Lengnau (AG)