
Sole proprietorship for agencies in Obermumpf: rules, deadlines, best practice
Sole proprietorship for agencies in Obermumpf raises the same questions for most Swiss SME owners: which obligations apply, which deadlines are running, which documents to prepare. This page covers the federal rules in force — without unnecessary jargon.
Choosing the structure: Sàrl, SA or sole proprietorship
Partners from day one? A shareholders' agreement settles what the articles do not: exit, deadlock, valuation. Signing it while everything is fine costs an evening; negotiating it in a crisis costs the company.
Sole proprietorship 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 sole proprietorship
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.
The law also settles the form: accounts may be kept in a national language or in English, on paper or electronically (art. 957a para. 5 CO). That pragmatism lets sole proprietorship run entirely on digital tools — no paper binder is required.
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.
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.

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 Obermumpf. They come on top of the federal social insurances and appear on every payslip.
For sole proprietorship, the gap between agreed gross and paid net surprises every new employer: simulate it BEFORE hiring to avoid misunderstandings with the future employee.
Obermumpf: what changes, what does not
Working with a fiduciary from Obermumpf no longer depends on geography: the documents of a business in Obermumpf are shared online, while the canton Aargau keeps its own deadlines for the tax return.
Federal deadlines do not move in Obermumpf: VAT within 60 days, salary declaration in January, 10-year record retention — postal code 4324 changes nothing about those rules, only the sender's address.
Frequently asked questions
How much does sole proprietorship cost in Obermumpf?
It depends on document volume, the number of salaries and VAT complexity — no serious figure can be quoted without examining the file. Two levers cut the bill everywhere: digitised, well-filed receipts and software that prepares entries instead of having them re-keyed.
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 Obermumpf.
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 Obermumpf, family allowances follow the canton's rates.
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 Obermumpf as everywhere 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 Obermumpf: AI-read documents, posting suggestions, VAT and exports ready for your fiduciary. Try the platform or browse our other guides.
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