Sole proprietorship for opticians in Sins: the practical guide
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on sole proprietorship in Sins: what the law requires, what can be automated, and when to delegate.
Choosing the structure: Sàrl, SA or sole proprietorship
Contributions in kind (vehicle, equipment, client portfolio) are possible when founding a Sàrl or an SA, but they follow strict valuation and disclosure rules. Cash contribution remains the simple route, in Sins as elsewhere.
On taxes, corporate profit bears direct federal tax at 8.5% (statutory rate) plus cantonal and communal tax — the total effective burden varies markedly between cantons. A realistic business plan and accounts kept from the start make bank credit noticeably easier.
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 Sins too.
For an SME in Sins, 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, sole proprietorship stops being a quarterly chore.
Digitalising sole proprietorship: what actually works
Artificial intelligence has changed the economics of sole proprietorship: automatic invoice reading reaches recognition rates that make manual entry marginal, and posting suggestions learn from corrections. The accountant does not disappear — the job shifts from data entry to control and advice.
Electronic archiving is fully recognised: Swiss bookkeeping regulation admits electronic retention of records provided integrity and readability are guaranteed for the 10 years of art. 958f CO. A paper binder is no longer an obligation — provided the archiving system is serious.
The Swiss legal frame for sole proprietorship
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. Sole proprietorship sits squarely within this frame, including for companies based in Sins.
For sole proprietorship, 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.
Sins: what changes, what does not
Working with a fiduciary from Sins no longer depends on geography: the documents of a business in Sins are shared online, while the canton Aargau keeps its own deadlines for the tax return.
For a business in Sins, that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Aargau.
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 Sins as anywhere.
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 Sins, family allowances follow the canton's rates.
Does MyFiducia.ai work for a business based in Sins?
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 Sins manages its documents, VAT and exports exactly as anywhere in Switzerland.
How long must records related to sole proprietorship 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 Sins can therefore archive fully digitally.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates sole proprietorship for businesses in Sins: 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.