
Tax advisory for architecture firms in Trin: rules, deadlines, best practice
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on tax advisory in Trin: what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for tax advisory
Swiss accounting law has been unified in the Code of Obligations since 2013: the same bookkeeping rules (art. 957a CO) and retention rules (art. 958f CO — 10 years for books, vouchers and reports) apply regardless of legal form. Tax advisory sits squarely within this frame, including for companies based in Trin.
The law also settles the form: accounts may be kept in a national language or in English, on paper or electronically (art. 957a para. 5 CO). That pragmatism lets tax advisory run entirely on digital tools — no paper binder is required.
A Swiss SME's accounting calendar
Three families of deadlines shape the year: federal (VAT within 60 days, salary declaration in January), cantonal (tax return, extensions depending on the canton, including in Trin) and internal (closing, general meeting within six months). Mixing them up is the leading cause of delays.
For a business in Trin, an isolated delay can be caught up; a structural delay is paid in interest, fines and stress. The difference between the two: a system, not good intentions.
Swiss VAT: rates, threshold and filings
The most frequent VAT mistakes are well known: the wrong rate among 8.1%, 2.6% and 3.8%, forgotten self-supplies, and a rushed annual reconciliation. Corrections are due at the latest in the return for the period containing the 180th day after the year-end — the earlier you correct, the less default interest runs.
The right reflex for tax advisory: file every supplier invoice with its VAT on receipt. Forgotten input VAT is money definitively lost once the limitation period runs out.

Year-end closing: how the mechanics work
Accrual accounting is the technical heart of the closing: every income and every expense belongs to the year it economically concerns, regardless of the payment date. Rents paid in advance, insurance premiums straddling the date, supplier invoices arriving in January: all flow through accrual accounts.
For tax advisory, a closing checklist reused every year transforms the exercise: same steps, same checks, same documents — only the year changes.
Trin: what changes, what does not
Working with a fiduciary from Trin no longer depends on geography: the documents of a business in Trin are shared online, while the canton Grisons keeps its own deadlines for the tax return.
For a business in Trin, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Grisons.
Frequently asked questions
What is simplified bookkeeping and who can use it?
Sole proprietorships and partnerships under CHF 500,000 of revenue may limit themselves to recording income, expenses and assets (art. 957 para. 2 CO). Once over the threshold — or upon founding a Sàrl or an SA — full accounts with balance sheet, income statement and notes become mandatory. The CHF 500,000 threshold is assessed the same way in Trin.
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 Trin too.
How much does tax advisory cost in Trin?
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.
Which documents should be prepared for the year-end closing?
Bank and cash statements at the closing date, the inventory of stock and work in progress, final AHV/LPP/accident settlements, contracts signed or amended during the year, invoices straddling two years and the detail of accruals. With an up-to-date document archive, most of it is already there. The list is identical in Trin: the CO dictates it, not the commune.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates tax advisory for businesses in Trin: 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.