
SME tax return deadlines in Romanshorn: the practical guide
Whether you run a Sàrl, an SA or a sole proprietorship in Romanshorn, SME tax return eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
The Swiss legal frame for SME tax return
In Switzerland, the duty to keep accounts stems from art. 957 ff. of the Code of Obligations. Legal entities (Sàrl, SA) and sole proprietorships with at least CHF 500,000 in revenue keep full accounts: balance sheet, income statement and notes. Below that threshold, a simplified record of income, expenses and assets is sufficient.
For SME tax return, the classic early mistake remains mixing private and business: a dedicated bank account and documented private withdrawals eliminate half the discussions with the tax office.
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 Romanshorn) and internal (closing, general meeting within six months). Mixing them up is the leading cause of delays.
For SME tax return, year-end is prepared in October: last invoices, investment decisions, provisions to assess — December is too late to act, January is for recording.
Swiss VAT: rates, threshold and filings
Registration happens with the Federal Tax Administration and yields a VAT number based on the business identifier (format CHE-xxx.xxx.xxx VAT). From then on, every invoice must state that number, the rate applied and the tax amount — three details SME tax return should lock down from day one to avoid retroactive fixes.
For an SME in Romanshorn, 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.

Year-end closing: how the mechanics work
Depreciation follows rates accepted by tax practice (property, machinery, IT): staying within those ranges avoids reassessments. Exceeding them is justified — and documented, in Romanshorn as anywhere.
A clean closing pays beyond the legal duty: it conditions the tax return, bank discussions and the company's value in a succession. Hidden reserves (accelerated depreciation, provisions) remain admissible within cantonal tax limits — document them systematically.
Romanshorn: what changes, what does not
Romanshorn (postal code 8590, canton Thurgau) applies the same federal rules as the rest of the country: what changes in Romanshorn are the cantonal counterparts — tax administration, compensation office, commercial register.
Romanshorn requires no special bookkeeping: the Code of Obligations applies at postal code 8590 as everywhere else, and a well-kept digital file transfers smoothly to any auditor in the canton.
Frequently asked questions
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 Romanshorn can therefore archive fully digitally.
Which social contributions does a Swiss employer pay?
AHV/IV/APG: 5.3% employer share (the same is withheld from the employee); unemployment insurance: 1.1% each up to CHF 148,200 a year; occupational pension (LPP) by age and plan (employer at least 50%); occupational accident insurance paid by the employer; family allowances by canton. For an employer in Romanshorn, family allowances follow the canton's rates.
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 Romanshorn as anywhere.
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 Romanshorn too.
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