
Accounting for law firms in Birmenstorf (AG): what every SME should know
Between VAT, social contributions and the year-end close, a Swiss SME juggles dozens of deadlines a year. This page focuses on accounting in Birmenstorf (AG): what the law requires, what can be automated, and when to delegate.
The Swiss legal frame for accounting
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.
Art. 957a CO requires complete, truthful and systematic recording of transactions, each entry backed by a supporting document. For accounting, that means in practice: no movement without a receipt, and an audit trail that can be reconstructed at any time — including during a VAT or AHV inspection.
A Swiss SME's accounting calendar
Extensions exist and can be requested: cantonal deadlines for the tax return, deferral of the VAT filing on a reasoned request. But an extension does not stop interest: on VAT, default interest runs from the ordinary due date even when more time has been granted.
Delays rarely come alone: neglected bookkeeping postpones the closing, hence the tax return, hence the recalculated instalments — and the business flies blind for months. Keeping the books current as you go is the only sustainable way to hold every cascading deadline.
A well-structured SME chart of accounts
The test of a good chart of accounts is a single question: can the owner find the margins in three clicks? If not, the chart serves the tax office but not the business — even in Birmenstorf (AG).
For a business in Birmenstorf (AG), comparability over time beats sophistication: a chart stable for five years beats a “perfect” one rebuilt every year. Banks and the tax administration read year-on-year movements first.

Digitalising accounting: 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.
For accounting, migrating history must not block the start: begin on day one of the current financial year and import the history later if needed.
Birmenstorf (AG): what changes, what does not
Birmenstorf (AG) (postal code 5413, canton Aargau) applies the same federal rules as the rest of the country: what changes in Birmenstorf (AG) are the cantonal counterparts — tax administration, compensation office, commercial register.
For a business in Birmenstorf (AG), that means VAT returns identical to anywhere in Switzerland, but a tax return and family allowances governed by the canton Aargau.
Frequently asked questions
Do you need a fiduciary for accounting, or can you do it yourself?
Both are defensible. Below CHF 500,000 of revenue, a sole proprietorship may keep simplified accounts itself. As soon as payroll, VAT and a closing with tax stakes are involved, professional support prevents mistakes that cost more than the fees. With a shared platform, the fiduciary does not even need to be in Birmenstorf (AG).
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 Birmenstorf (AG) as everywhere in Switzerland.
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 Birmenstorf (AG), family allowances follow the canton's rates.
How long must records related to accounting 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 Birmenstorf (AG) can therefore archive fully digitally.
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Switch to accounting that keeps itself up to date
MyFiducia.ai automates accounting 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.