
SME tax return online in Altnau: the practical guide
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
AHV audits and VAT audits follow the same logic: start from the documents, trace to the entries, check consistency. A business in Altnau with a clean audit trail sails through these exercises.
Also worth knowing: accounts may be drawn up in the currency most relevant to the business; if that is not the franc, values must additionally be stated in CHF (art. 958d para. 3 CO). Internationally active companies gain books that match their economic reality.
A Swiss SME's accounting calendar
The professionals' trick: handle every deadline at D-30, not D-1. A VAT return prepared a month early leaves time to chase a missing document without penalty.
For SME tax return, two dates lock themselves in every year: the January salary declaration and the general meeting within six months — everything else is planned around them.
Swiss VAT: rates, threshold and filings
A VAT return is prepared, not endured: clean VAT accounts, one code per rate and a monthly variance check make the deadline trivial — for registered businesses in Altnau too.
For an SME in Altnau, electronic filing of VAT returns has been mandatory since 1 January 2025; the tax administration's online portal is also where extensions are requested and past periods consulted. Combined with accounts that prepare the return automatically, SME tax return stops being a quarterly chore.

Outsource SME tax return 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 Altnau as elsewhere.
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.
Altnau: what changes, what does not
Sole proprietorship, Sàrl or SA in Altnau: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Thurgau.
For a business in Altnau, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Thurgau.
Frequently asked questions
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.
Does MyFiducia.ai work for a business based in Altnau?
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 Altnau manages its documents, VAT and exports exactly as anywhere in Switzerland.
When must a business register for VAT?
As soon as its worldwide annual turnover reaches CHF 100,000 (CHF 250,000 for non-profit sports or cultural associations). Below that, voluntary registration remains possible and often makes sense to reclaim input VAT on investments. The threshold is federal: it applies in Altnau as everywhere in Switzerland.
Also worth reading
In neighbouring municipalities
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.