Opening a business in Solothurn: registration and costs

Context

In brief

• Three main legal forms (sole proprietorship, LLC, corporation) with different minimum capitals and liabilities
• Registration with the commercial register within 30 days of starting operations
• Taxation on three levels: federal (IFD) + cantonal (Solothurn) + municipal (variable multipliers)
• Mandatory social contributions: AVS/AI 5.3% for employees, SUVA, LAMal within 3 months

Key facts

• What: Starting a business in the canton of Solothurn with commercial registration
• When: Registration within 30 days of starting operations
• Where: Solothurn cantonal commercial register office
• Who: Aspiring entrepreneur residing or with a valid federal permit
• Legal forms: Sole proprietorship (no minimum capital), LLC (min. CHF 20,000), Corporation (min. CHF 100,000)
• AVS/AI contributions: 5.3% of employee salary; 10.6% total with employer

Starting a business in the canton of Solothurn — whether as a sole proprietorship, limited liability company (LLC), or corporation — requires compliance with precise administrative procedures and federal, cantonal, and municipal tax payments. The first step is registration with the cantonal commercial register, mandatory within 30 days of starting operations. Subsequently, tax declaration obligations and social contribution payments (AVS/AI/IPG, SUVA, LAMal, LPP if hiring employees) begin.

Legal forms: which to choose

The choice of legal form depends on the level of personal liability you are willing to accept, the initial capital available, and the organizational complexity of the business.

The sole proprietorship is the simplest form: a single natural person, unlimited liability for commercial debts, no mandatory minimum capital. Income is taxed directly on personal assets according to IFD (direct federal tax) rules. It is the preferred choice for self-employed professionals, consultants, and small business owners.

The LLC (limited liability company) is a legal entity distinct from the owner. Minimum capital: CHF 20,000, with at least 50% paid at the time of founding. Liability is limited to the paid-in capital. Each partner holds shares and is not personally liable for business debts beyond the paid-in capital.

The corporation is suitable for medium to large-scale projects with growth potential. Minimum capital: CHF 100,000, divided into registered or bearer shares. Requires a board of directors and a shareholders' meeting. Liability for shareholders is limited to the subscribed capital.

Registration procedure

Registration with the Solothurn cantonal commercial register is done through the cantonal commercial register office. Required documents include: valid ID, articles of association and bylaws (for corporations), simple or digitally signed declaration of business start, brief description of the activity, legal address, bank details. The registration fee varies by canton and municipality (to be verified directly with the office).

After registration, the cantonal administration automatically transmits the registration data to the Federal Customs Administration (FCA/ESTV) for VAT registration if the annual turnover exceeds CHF 100,000 in 12 consecutive months. Simultaneously, it is mandatory to register with the AVS/AI/IPG system within 5 days of hiring the first employee; if you are self-employed, registration occurs immediately. Delays in these procedures result in fines and late interest.

Operational details

Federal, cantonal, and municipal taxation

Swiss taxation follows a three-tier model. The direct federal tax (DFT), managed by the Federal Customs Administration (FCA), applies to net income and assets according to federal rates uniform across the country. In the canton of Solothurn, the cantonal tax is levied according to the canton's own rate, which varies from canton to canton. Finally, each municipality applies its own multiplier to the cantonal rate: the taxpayer pays the cantonal tax amount multiplied by the municipal coefficient. The municipal multipliers in Solothurn vary from municipality to municipality; it is essential to verify them with the Tax Office of the municipality where the activity will be conducted before starting operations.

The value-added tax (VAT), managed by the FCA, applies when the turnover exceeds CHF 100,000 in 12 consecutive months (mandatory registration), or voluntary registration can be requested if more convenient for the activity. VAT does not constitute an additional tax cost for the company but rather a periodic declaration procedure (quarterly or annual depending on the chosen regime) with the right to deduct qualified purchases.

Social contributions: AHV, IV, EO, SUVA, LAA, LAMal

If you are the owner of a self-employed activity, you are automatically enrolled in the AHV/IV/EO system (Old-Age and Survivors' Insurance, Disability Insurance; Maternity/Paternity Allowance according to federal law EO). The contributions are:

• AHV/IV/EO: 5.3% on the annual net income of the self-employed. If you hire employees, you pay 5.3% (employee's share) + 5.3% (employer's share) = 10.6% total on the coordinated salary. Annual coordinated maximum set annually by the Confederation (approximately CHF 149,080 in 2026, indexed every year).
• Unemployment insurance (UI): 1.1% up to the annual maximum, applicable if you have employees. Employee's share + employer's share.
• SUVA (workplace accidents, managed by the Swiss National Accident Insurance Institute): 0.7–1.5% of the gross salary depending on the sector of activity and the degree of risk.
• LAMal (mandatory health insurance): Binding for all residents within 3 months of starting the activity. It is not a tax or a salary contribution but rather a private insurance with per capita premiums varying by canton and region. Deductibles for adults: from CHF 300 to CHF 2,500 annually at choice. Cantonal subsidies available based on income.
• LPP (mandatory occupational pension): If you hire employees with a coordinated salary above CHF 21,330 (2026, indexed annually), you must enroll the company in a recognized pension institution. Contribution rate varies by age bracket of the employee: 7% (25–34 years), 10% (35–44), 15% (45–54), 18% (55+ up to the reference age). Contributions divided into employee's share/employer's share.

Practical scenario: sole proprietorship vs. LLC

A sole proprietorship with a single owner pays self-employed AHV/IV/EO contributions (5.3% on net income). If it hires an employee with an annual gross salary of CHF 60,000, the owner continues to pay AHV/IV/EO on their own income and simultaneously pays 10.6% (AHV/IV/EO) + about 1% (UI) + 0.7–1.5% (SUVA) on the employee's salary, plus LPP if the coordinated salary exceeds CHF 21,330. An LLC with one or more partners follows the same social contribution rules for employees. The main difference is that the LLC is a legal entity separate from the owner: the owner receives dividends or profit distributions (not directly salary), subject to different federal/cantonal taxation compared to employment income.

Useful planning tools

To estimate your pension strategy, use the pension planner and the pillar 3 simulator.

Key points

Step-by-step procedure: from registration to first deadlines

Starting a business in the canton of Solothurn requires the orderly completion of these steps:

1. Choose the legal form (sole proprietorship, LLC, Corporation). If you opt for a company, consult a notary or accounting firm for the drafting of the articles of association and the bylaws (mandatory for companies).

2. Register with the commercial register of the canton of Solothurn within 30 days of the actual start of the activity. Provide: valid ID document, articles of association and bylaws (for companies), declaration of start of activity, brief description of the activity, legal address, bank details. Registration involves a cost that varies by canton and municipality (to be verified with the cantonal commercial register office).

3. Register with AVS/AI/IPG within 5 days of hiring the first employee, or immediately if you are self-employed. AVS-100 form available at the cantonal AVS office of the canton of Solothurn. Provide social security number, personal data, company data.

4. Apply for VAT registration (if the estimated turnover exceeds CHF 100,000 annually or voluntary choice). Application with the Federal Customs Administration (FCA/ESTV), form available online.

5. Register staff with SUVA/LAA and ensure accident coverage from the first day of work. Registration with SUVA (if not employed in agriculture) or LAA.

6. Take out health insurance (LAMal) within 3 months of the start of operational activity. Mandatory for the owner and employees resident in Switzerland. Choose a fund from those authorized in the canton, considering the deductible and premium.

7. Periodic payments and declarations:

• AVS/AI/IPG contributions: monthly by the 10th of the following month (different frequency possible by agreement).
• VAT declaration: quarterly or annual according to turnover and chosen regime.
• Annual tax return: by the cantonal deadline (usually March of the following year for the previous fiscal year).

Where to find help and verify local data

Consult the Swiss tax and contribution calculator for an accurate estimate of your federal/cantonal/municipal tax burden based on expected net income and the canton of operation. The cantonal commercial register office of Solothurn provides updated forms, detailed instructions, and direct advice for registration. The cantonal AVS office, the cantonal tax office, and the Federal Customs Administration (FCA/ESTV) are essential resources for tax declarations and payments.

Each canton and each municipality of Solothurn has its own multipliers, cantonal rates, tax breaks, and subsidies. Before formally starting the activity, contact the tax office of your municipality to verify the exact multipliers, applicable deductions (operating expenses, depreciation, passive interest), and available cantonal subsidies (e.g., LAMal premium reduction for low incomes, incentives for new businesses). A local accountant or tax advisor speeds up the administrative process and avoids costly errors.