
Everything that matters about e-invoicing for construction companies in Lommis
Swiss accounting law (art. 957 ff. of the Code of Obligations) sets a precise frame, yet day-to-day practice often stays fuzzy. This guide walks through what actually matters for a business based in Lommis.
Digitalising e-invoicing: what actually works
Security is part of digitalisation: named access, tested backups, encryption of sensitive data. A digital accounting file is protected like a safe — because it is one.
For e-invoicing, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
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 e-invoicing, 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 e-invoicing
AHV audits and VAT audits follow the same logic: start from the documents, trace to the entries, check consistency. A business in Lommis 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 e-invoicing, 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
Account labels deserve as much care as numbers: “Third-party fees” says nothing, “Fiduciary fees” and “IT fees” say everything. Meaningful labels cut posting errors and make dashboards readable without a glossary.
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.
Lommis: what changes, what does not
Working with a fiduciary from Lommis no longer depends on geography: the documents of a business in Lommis are shared online, while the canton Thurgau keeps its own deadlines for the tax return.
Federal deadlines do not move in Lommis: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 9506 changes nothing about those rules, only the sender's address.
Frequently asked questions
Can e-invoicing be automated with AI?
Largely, yes: automatic document reading, posting suggestions, bank reconciliation via QR references and VAT exports. Human approval remains essential — AI prepares, the professional checks. That is exactly how MyFiducia.ai approaches e-invoicing.
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 Lommis too.
How much does e-invoicing cost in Lommis?
It depends on document volume, the number of salaries and VAT complexity — no serious figure can be quoted without examining the file. Two levers cut the bill everywhere: digitised, well-filed receipts and software that prepares entries instead of having them re-keyed.
Do you need a fiduciary for e-invoicing, 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 Lommis.
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MyFiducia.ai automates e-invoicing for businesses in Lommis: 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.