
Everything that matters about e-invoicing for architecture firms in Lengnau (AG)
Whether you run a Sàrl, an SA or a sole proprietorship in Lengnau (AG), e-invoicing eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
Digitalising e-invoicing: what actually works
Automation is judged on the exceptions: what happens when the document is unreadable, the supplier unknown, the amount divergent? A good tool isolates those cases and lets a human decide fast — precious for teams in Lengnau (AG).
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.
Outsource e-invoicing or keep it in-house?
The scope goes down in writing: who enters data, who approves payments, who answers the tax office, who keeps the originals. Every “we'll see” at the start becomes a December misunderstanding — in Lengnau (AG) as elsewhere.
A business in Lengnau (AG) can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — e-invoicing splits very well.
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.

A well-structured SME chart of accounts
The test of a good chart of accounts is a single question: can the owner find the margins in three clicks? If not, the chart serves the tax office but not the business — even in Lengnau (AG).
The chart of accounts is also the hinge to VAT: every revenue account carries its rate (8.1%, 2.6%, 3.8% or exempt), every expense account its input-tax right. Set those attributes once in the tool and every subsequent return becomes reliable.
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
What are the legal obligations for e-invoicing 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.
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.
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 Lengnau (AG).
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.
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In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates e-invoicing 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.