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SME tax return for architecture firms in Altnau: what every SME should know

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 Altnau.

The Swiss legal frame for SME tax return

Responsibility for the books is personal: in an SA, organising the accounting is one of the board's non-transferable duties (art. 716a CO); in a Sàrl, the managing directors carry the same duty. Outsourcing the execution never transfers that underlying responsibility, including for a company based in Altnau.

One simple principle drives SME tax return: every franc in or out must be explainable by a document, an entry and an account. All of Swiss accounting law fits inside that traceability requirement.

Outsource SME tax return or keep it in-house?

The Swiss fiduciary market is dense and governed by professional practice: industry standards, business secrecy, civil liability. Compare offers on three concrete criteria — exact scope (data entry? closing? payroll? VAT?), a named contact person, and the tools used. It prevents year-end misunderstandings.

A business in Altnau can combine the models: internal day-to-day entry, monthly external supervision, closing and taxes with the specialist — SME tax return splits very well.

A Swiss SME's accounting calendar

Extensions exist and can be requested: cantonal deadlines for the tax return, deferral of the VAT filing on a reasoned request. But an extension does not stop interest: on VAT, default interest runs from the ordinary due date even when more time has been granted.

For a business in Altnau, 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.

Collaborative desk with laptops and documents, top view

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.

A business in Altnau that crosses the threshold mid-year must register without delay: retroactive registration with interest always costs more than signing up on time.

Altnau: what changes, what does not

Altnau (postal code 8595, canton Thurgau) applies the same federal rules as the rest of the country: what changes in Altnau are the cantonal counterparts — tax administration, compensation office, commercial register.

Federal deadlines do not move in Altnau: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 8595 changes nothing about those rules, only the sender's address.

Frequently asked questions

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 Altnau too.

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 Altnau as anywhere.

How long must records related to SME tax return 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 Altnau can therefore archive fully digitally.

Can SME tax return 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 SME tax return.

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Switch to accounting that keeps itself up to date

MyFiducia.ai automates SME tax return for businesses in Altnau: 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.