This page inFRDEENAR

Two people reviewing numerical reports

SA incorporation for e-commerce in Birmenstorf (AG) explained simply

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 Birmenstorf (AG).

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 Birmenstorf (AG) as elsewhere.

SA incorporation starts on day one: founding capital, notary and register fees are the first entries. Opening a separate business bank account immediately — even for a sole proprietorship — saves hours of sorting private from business.

The Swiss legal frame for SA incorporation

For an owner in Birmenstorf (AG), the question is never “do we need accounts?” but “at what level of detail?”. The CO sets the floor; the bank, the tax office and the shareholders set the rest.

The annual accounts (art. 958 CO) consist of the balance sheet, the income statement and the notes; they must be drawn up within six months of the year-end so the general meeting can approve them. A delay here cascades into the tax return and the final social insurance settlements.

Swiss VAT: rates, threshold and filings

Exports, services abroad, acquisition tax: as soon as anything international enters the picture, VAT gets demanding (place of supply, acquisition tax on services). Better to set the rules once with a professional than to correct three financial years.

For an SME in Birmenstorf (AG), 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, SA incorporation stops being a quarterly chore.

Smiling team looking at a laptop

Salaries and social contributions: the rates to know

Family allowances are financed by the employer through a cantonal compensation fund — rates and amounts vary from canton to canton, including in Birmenstorf (AG). They come on top of the federal social insurances and appear on every payslip.

For SA incorporation, the winning mechanics are simple: one single payroll database (salaries, rates, allowances), monthly slips generated from it, and an annual declaration that is little more than a sum. Painful catch-up invoices almost always stem from scattered data.

Birmenstorf (AG): what changes, what does not

Sole proprietorship, Sàrl or SA in Birmenstorf (AG): the AHV contact remains the competent compensation office, and taxes follow the scales of the canton Aargau.

Federal deadlines do not move in Birmenstorf (AG): VAT within 60 days, salary declaration in January, 10-year record retention — postal code 5413 changes nothing about those rules, only the sender's address.

Frequently asked questions

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 Birmenstorf (AG): the CO dictates it, not the commune.

Does MyFiducia.ai work for a business based in Birmenstorf (AG)?

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 Birmenstorf (AG) manages its documents, VAT and exports exactly as anywhere in Switzerland.

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 Birmenstorf (AG) as anywhere.

What is simplified bookkeeping and who can use it?

Sole proprietorships and partnerships under CHF 500,000 of revenue may limit themselves to recording income, expenses and assets (art. 957 para. 2 CO). Once over the threshold — or upon founding a Sàrl or an SA — full accounts with balance sheet, income statement and notes become mandatory. The CHF 500,000 threshold is assessed the same way in Birmenstorf (AG).

Also worth reading

In neighbouring municipalities

Switch to accounting that keeps itself up to date

MyFiducia.ai automates SA incorporation for businesses in Birmenstorf (AG): 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.

    SA incorporation for e-commerce in Birmenstorf (AG)