
Everything that matters about sole proprietorship for architecture firms in Eppenberg-Wöschnau
Whether you run a Sàrl, an SA or a sole proprietorship in Eppenberg-Wöschnau, sole proprietorship eventually lands on your desk. Here are the practical reference points — legal basis, deadlines and common pitfalls — to decide with a clear head.
Choosing the structure: Sàrl, SA or sole proprietorship
Articles and internal organisation are written to last: circle of shareholders, transfer of shares, signature rights. Templates do the job at first, but every missing clause gets renegotiated later from a weaker position.
From day one, three administrative tracks open: affiliation to an AHV compensation office, review of VAT liability (CHF 100,000 threshold) and setting up the accounts. Handling sole proprietorship from the first month costs far less than reconstructing a whole year in December.
Salaries and social contributions: the rates to know
The salary certificate is an official tax document: it feeds the employee's tax return and serves as the reference in AHV and tax audits. Issued once a year, it must match payroll accounting and the declaration to the compensation office to the centime.
For sole proprietorship, the monthly payslip is only the visible part: instalments to the funds, annual settlements and certificates form the real cycle, January to January.
Digitalising sole proprietorship: what actually works
A serious accounting document archive links every record to its entry, timestamps versions and logs access — exactly what Swiss bookkeeping regulation expects from probative electronic retention. Chronological filing by financial year becomes an automatic by-product.
An SME in Eppenberg-Wöschnau that digitalises gains owner time first: less filing, fewer “where is that receipt?” questions, more attention to the trade — that is the real return of sole proprietorship.

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 sole proprietorship should lock down from day one to avoid retroactive fixes.
The right reflex for sole proprietorship: file every supplier invoice with its VAT on receipt. Forgotten input VAT is money definitively lost once the limitation period runs out.
Eppenberg-Wöschnau: what changes, what does not
Sole proprietorship, Sàrl or SA in Eppenberg-Wöschnau: the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Solothurn.
Federal deadlines do not move in Eppenberg-Wöschnau: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5012 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 Eppenberg-Wöschnau too.
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 Eppenberg-Wöschnau: the CO dictates it, not the commune.
Effective VAT method or net tax rate: how to choose?
The effective method deducts actual input VAT and files quarterly; the net tax rate method applies a flat industry rate to turnover, semi-annually, with no separate input VAT deduction. The flat rate suits low-cost structures; as investments grow, the effective method usually wins again. The choice rests on the company's own figures, in Eppenberg-Wöschnau as anywhere.
Does MyFiducia.ai work for a business based in Eppenberg-Wöschnau?
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 Eppenberg-Wöschnau manages its documents, VAT and exports exactly as anywhere in Switzerland.
Also worth reading
In neighbouring municipalities
Switch to accounting that keeps itself up to date
MyFiducia.ai automates sole proprietorship for businesses in Eppenberg-Wöschnau: 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.