The self-employed tax return: why it's different
Anyone running a self-employed business in Switzerland — sole proprietorship, freelancer or independent professional — faces a far more complex tax return than an employee. Simply entering a salary certificate isn't enough: you must complete the specific supplement for self-employment (Fragebogen für Selbstständigerwerbende), submit a detailed income statement and justify every deduction with supporting documentation.
The Swiss tax system requires the self-employed to independently determine their net business income: revenues minus professional expenses, depreciation, provisions and social security contributions (AHV/IV/EO). Errors in calculation or expense classification can lead to tax adjustments, default interest and, in the most serious cases, criminal proceedings for tax evasion.
The good news is that structured accounting software can automatically prepare all the required data — from the income statement to expense category totals — ready to be transferred to the cantonal tax return or eTax software. This guide explains the process step by step and how to simplify it.
Tax forms for the self-employed
Unlike employees, self-employed workers must complete supplementary forms attached to the standard tax return. The documentation varies slightly from canton to canton, but the basic structure is the same throughout Switzerland:
Main tax return
The base form is the same as for employees: personal data, marital status, children, investment income, personal deductions (pillar 3a, health insurance, debt interest). The self-employed person reports their net business income here, as calculated in the specific supplement.
Self-employment supplement
The key form: it contains the business income statement (revenues, cost of goods, personnel expenses, depreciation, general expenses), the operating result and tax adjustments. In many cantons it is called 'Fragebogen für Selbstständigerwerbende' or 'Annexe activité indépendante'.
Depreciation and provisions schedule
A detailed list of all depreciable assets (vehicles, equipment, furniture, software) with initial value, applied depreciation rate and residual value. Rates must comply with the federal FTA tables (Circular No. 12).
Securities and business assets list
If the self-employed person holds business assets (real estate, participations, trade receivables), these must be declared separately from private assets. The distinction is crucial because business assets are subject to different tax rules (e.g. for real estate capital gains).
Calculating taxable income
Net self-employment income is the basis for income tax calculation. Here are the five steps to determine it correctly:
Gross business revenues
Sum of all invoices issued in the tax year (accrual basis), including ancillary revenues, insurance indemnities received and gains on the sale of business assets. If VAT-registered, revenues should be reported net of tax.
Deduction of direct costs
Cost of goods, raw materials, subcontractors and third-party services directly linked to revenues. The result is the gross profit (commercial margin). Every cost must be supported by documentation.
Deduction of general expenses
Office/workshop rent, professional insurance, business vehicle costs, telephone and internet, office supplies, software, continuing education, entertainment and advertising expenses. Also includes compliant depreciation and provisions.
Deduction of social security contributions
The self-employed person personally pays AHV/IV/EO contributions (total rate of 10.6% on income above CHF 58,800) and daily sickness/accident allowance. These contributions are fully deductible from business income. Voluntary LPP (2nd pillar) and pillar 3a contributions are also deductible within legal limits.
Net business income
The final result (revenues – direct costs – general expenses – social contributions) equals net self-employment income, which is carried over to the main tax return. Any other income (investments, pensions) is added to obtain total taxable income.
Allowable deductions for the self-employed
Self-employed persons can deduct all professionally justified expenses. Here are the main categories with their limits and conditions:
| Expense category | Deductible | Max amount / Notes |
|---|---|---|
| Office rent / coworking | ✓ | Full amount if exclusively professional use; proportional share if mixed home-office use (max 20–40% of rent) |
| Business vehicle | ✓ | Actual costs (leasing, fuel, insurance, maintenance) or CHF 0.70/km; mandatory reduction for private use |
| AHV/IV/EO contributions | ✓ | Fully deductible from business income — rate 10.6% (income > CHF 58,800) |
| Pillar 3a (self-employed without LPP) | ✓ | Max CHF 36,288 (2026) for self-employed not affiliated with a pension fund (20% of net income) |
| Depreciation of business assets | ✓ | Max rates set by FTA: furniture 25%, vehicles 40%, equipment 30%, software 40% (declining balance) |
| Continuing education expenses | ✓ | Max CHF 12,900 (federal deduction); courses directly related to professional activity |
| Off-site meals | ✓ | Max CHF 15/meal for documented business trips (no flat rate for self-employed) |
| Entertainment / client gifts | Partial | Deductible only if professionally justified and proportionate; the tax authority may challenge excessive amounts |
Provisional payments and deadlines
In Switzerland, income taxes are not withheld at source for the self-employed (with exceptions for foreigners with B permits). The self-employed person must make provisional payments (Vorauszahlungen / acomptes provisoires) during the tax year:
Calculation of provisional payments
The canton sends a provisional invoice based on the previous year's tax return. If the current year's income will be significantly different, it is possible — and advisable — to request an adjustment of the instalments to avoid surprises.
Payment schedule
Most cantons provide quarterly payments (March, June, September, December), but some offer monthly instalments. Zurich sends 2 payment slips (March and September), Bern 3 instalments, Vaud and Ticino generally 3–4 instalments. Always check the cantonal calendar.
Compensatory and default interest
Paying early earns compensatory interest (variable rate, around 0.5–1.5% in 2026 depending on the canton). Conversely, late payments incur default interest (1–4.5% per year). For large amounts, the difference can be hundreds of francs.
Final settlement
After the definitive assessment (often 12–18 months after filing), the canton issues the tax decision. If the instalments were insufficient, the difference is due within 30 days with default interest from the original due date. If they were excessive, the canton refunds with compensatory interest.
Warning: if your income has grown significantly, failing to adjust your provisional payments can lead to an unexpected tax debt of several thousand francs. AccountEX shows a real-time estimate of annual profit, allowing you to anticipate the adjustment.
Cantonal differences: deadlines and forms
Each canton has its own deadlines, forms and software for the tax return. Here is a comparison of the four main cantons for self-employed workers:
| Canton | Filing deadline | Software / Forms | Specific rules |
|---|---|---|---|
| Zurich (ZH) | 31 March (extension until 30 September on request) | ZHprivateTax (online) + Fragebogen für Selbstständigerwerbende | Balance sheet mandatory for revenues > CHF 500,000; depreciation only with detailed schedule; 2 instalment payments (March, September) |
| Bern (BE) | 15 March (extension until 15 September for CHF 40 fee) | TaxMe Online + self-employment supplement | Simplified accounting permitted below CHF 500,000 revenue; 3 instalment payments; default interest 3.0% |
| Vaud (VD) | 15 March (free extension until 30 June) | VaudTax + Annexe activité indépendante | Mandatory attachment of income statement and balance sheet; depreciation per FTA tables; 4 quarterly instalment payments |
| Ticino (TI) | 30 April (extension until 30 September on justified request) | eTax TI (desktop) + form 2A (self-employment) | Form 2A requires detailed income statement and depreciation schedule; 3 instalment payments; default interest 2.5% |
From AccountEX to eTax: automatic preparation
AccountEX automatically generates all the data needed to complete the self-employed tax return, eliminating hours of manual work and the risk of transcription errors:
Tax income statement
AccountEX's chart of accounts is preconfigured for the structure required by cantonal forms. At year-end, the income statement is ready with the correct categories: revenues, cost of goods, personnel expenses, depreciation, general expenses — in the exact totals required by the self-employment form.
Automatic depreciation schedule
Every registered business asset automatically generates the depreciation calculation according to FTA rates. The schedule is exportable as PDF with initial value, annual depreciation and residual value — ready to be attached to the tax return.
Deduction summary by category
All expenses are classified by tax category (vehicle, office, education, entertainment). At year-end, a dedicated report shows totals for each deductible item, with linked supporting documents for any audits.
AHV/IV contribution calculation
Based on the estimated net profit, AccountEX calculates the AHV/IV/EO contributions due and shows the corresponding deduction. This provides a precise estimate of net business income even before receiving the definitive invoice from the compensation office.
Data export for eTax
The generated totals can be exported in a format compatible with the main cantonal tax software (eTax TI, ZHprivateTax, TaxMe, VaudTax). Simply copy the values into the corresponding fields — no manual recalculation needed.
Digital document archive
Every invoice, receipt and bank statement is digitally archived with a direct link to the accounting entry. In the event of a tax audit, you can trace from the declared total to the individual supporting document in a few clicks.
AccountEX does not file your tax return for you (that remains the task of your fiduciary or yourself as taxpayer), but it prepares all the data so that filing becomes a simple transfer of figures — reducing preparation time from days to minutes.
7 practical tips for your tax return
- Record every expense when it occurs: waiting until year-end means forgetting deductions and losing receipts. With AccountEX, just photograph the receipt and the entry is created automatically.
- Strictly separate personal from business expenses: a dedicated bank account for the business is the simplest way to avoid disputes in the event of an audit.
- Request an adjustment of your provisional payments if your income has grown or fallen significantly compared to the previous year — you'll avoid surprises at settlement time.
- Check depreciation rates before applying them: rates exceeding those in FTA Circular No. 12 will be systematically corrected by the tax authority.
- Keep supporting documents for at least 10 years: even after the definitive assessment, the authority can reopen the case within the statute of limitations (5 years ordinary, 15 years for tax evasion).
- Maximise your pillar 3a: if you're not affiliated with a pension fund (LPP), you can deduct up to CHF 36,288 in 2026 — a tax saving that can exceed CHF 10,000 depending on the canton.
- Consult a fiduciary for your first self-employed tax return: the initial investment (CHF 500–1,500) saves you from costly mistakes and teaches you the structure for subsequent years.
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