
E-invoicing for engineering firms in Trey: rules, deadlines, best practice
Delegate, digitalise or do it all yourself? Around e-invoicing in Trey, every SME draws its own line. The reference points below — federal law, cantonal practice and lessons from the field — help you place the cursor well.
Digitalising e-invoicing: what actually works
A serious accounting document archive links every record to its entry, timestamps versions and logs access — exactly what Swiss bookkeeping regulation expects from probative electronic retention. Chronological filing by financial year becomes an automatic by-product.
The winning pair for e-invoicing: a single inbox (e-mail, scan, photo) and one simple rule — no document sits more than a few days without a proposed entry.
A well-structured SME chart of accounts
The same chart serves three readings: accounting (accuracy), tax (accepted adjustments) and management (margins by activity). Modern software produces all three views without double entry.
Suspense accounts (to clarify) are useful provided they are emptied monthly: a swelling “miscellaneous” account is the classic symptom of a chart that no longer fits the activity.
Outsource e-invoicing or keep it in-house?
A good test before choosing: ask the fiduciary HOW it wants to receive the documents. A precise answer (formats, frequency, platform) says more than any brochure — including in Trey.
Changing fiduciary is not a drama: the accounting data belongs to the company, and a clean export (entries, chart of accounts, linked documents) allows a transition at year-end. A provider who locks in a client's data says a lot about how it works.

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, invoicing fast changes everything: a service billed the week it is delivered gets paid noticeably earlier than a month-end batch invoice.
Trey: what changes, what does not
Working with a fiduciary from Trey no longer depends on geography: the documents of a business in Trey are shared online, while the canton Vaud keeps its own deadlines for the tax return.
For a business in Trey, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Vaud.
Frequently asked questions
How much does e-invoicing cost in Trey?
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.
What are the current Swiss VAT rates?
Since 1 January 2024: 8.1% (standard), 2.6% (reduced — for example food and medicines) and 3.8% (accommodation). Returns must be filed and paid within 60 days after the period ends (quarterly under the effective method, semi-annually under the net tax rate method). These federal rates apply unchanged in Trey.
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 Trey: federal law applies.
Does MyFiducia.ai work for a business based in Trey?
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 Trey manages its documents, VAT and exports exactly as anywhere in Switzerland.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates e-invoicing for businesses in Trey: 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.