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Guide · Receipts and taxes

Tax return for the self-employed: a guide

When you're self-employed, your tax return involves more than a salary certificate and a few deductions: you declare your business profit, document your costs and add back private use. What you need to include, which deductions you can claim and why the AHV (old-age and survivors' insurance) only issues its final bill after your tax assessment.

Alain SchneebergerUpdated: 7 min read

Key points at a glance

  • Your tax return must include a form or supplementary sheet for the self-employed and your annual financial statements - or, if you keep simple accounts, a statement of income, expenses and assets (Art. 125 para. 2 DBG, Federal Act on Direct Federal Taxation, in German).
  • You can deduct all costs justified by your business (Art. 27 DBG) - but you add back any portion used privately, for example for your car, as a private share.
  • If you don't belong to a pension fund (Pensionskasse), you can pay up to 20% of your net earned income, at most CHF 36'288, tax-free into pillar 3a in 2026.
  • The compensation office (Ausgleichskasse) only calculates your final AHV contributions after your tax assessment.

What your tax return needs to include

As a self-employed person, you fill in an additional form about your business on top of the regular tax return. The canton of Zurich, for example, requires Hilfsblatt A (supplementary sheet A, in German) - in one version for full commercial bookkeeping and one for simplified bookkeeping. Other cantons have similar forms; you can get them from your cantonal tax office or in your canton's tax software.

You also enclose your annual financial statements, i.e. the balance sheet and income statement. If you only keep simple accounts (allowed up to CHF 500'000 in revenue, Art. 957 para. 2 of the Swiss Code of Obligations, CO), a statement of income and expenses, assets and liabilities, and private withdrawals and contributions is enough (Art. 125 para. 2 DBG). You only submit the receipts themselves on request, but you must keep them for 10 years (Art. 958f CO).

Deductions you can claim

Don't forget private shares

If you use something for both business and private purposes, you can only deduct the business portion. This most often affects:

  • Company car: a flat rate of 0.9% of the purchase price (excluding VAT) per month, at least CHF 150 - as set out, for example, in Directive ZStB 17.1 of the canton of Zurich (in German). Alternatively, you can prove your private use with a logbook. Read more in our article Mileage claims.
  • Phone, internet, laptop: Deduct a reasonable private share.
  • Goods taken for private use: Anything you take from your own business for private use counts as income.

Example: graphic designer with a company car

Lea has CHF 82'000 in income for the year. Her expenses are CHF 21'000, including CHF 1'600 in depreciation on her laptop and monitor and CHF 6'500 in car costs. Her car cost CHF 30'000; she adds back 0.9% × 12 = CHF 3'240 as the private share. This makes her profit from self-employment CHF 64'240. In her tax return, she then deducts her AHV contributions and her pillar 3a payment, among other things.

Deadlines and extensions

Each canton sets its own deadline. In the canton of Zurich, for example, you must file your tax return by March 31 of the following year; if you need more time, you request an extension - before the deadline expires, otherwise the request will no longer be considered. Most cantons let you do this online. For the self-employed, the annual financial statements often take longer - so plan for the extension early.

After the assessment: the AHV settles up

During the year, you only pay provisional AHV contributions. Once your tax assessment is final, the tax authority reports your earned income to the compensation office (Art. 23 AHVV, AHV Ordinance, in German). The compensation office then calculates your final contributions and bills you for the difference - or credits it to you. If your profit differs significantly from the estimate, let the compensation office know early so your provisional contributions can be adjusted. Read more in AHV/IV leaflet 2.02.

Common mistakes

  • Private costs as business expenses: vacations, personal clothing or the family phone don't belong in your business accounts.
  • Missing receipts: The tax office can disallow anything you can't document.
  • Forgetting private shares, especially for the car.
  • Wrong pillar 3a maximum: The higher amount only applies if you don't belong to a pension fund.
  • No reserve for AHV back payments: They often only arrive one to two years later.

How it works in Easly

Easly collects everything you need for your tax return throughout the year and gives it to you or your accountant ready to use:

  • Income statement as PDF and Excel, with drill-down to individual receipts. Income counts from the date of payment; salaries, mileage and home office costs are included automatically.
  • Individual reports: invoice overview and mileage as Excel, VAT return as PDF and Excel, salary certificates (Lohnausweis) as PDF in the personnel file, and a fixed asset register of your equipment.
  • Complete export: All data as Excel and CSV and all receipts as original files in one ZIP file - ideal for your accountant.
Expense list in Easly with extracted receipts, categories and amounts (enlarge image)

What Easly doesn't do for you

Easly doesn't fill in your tax return or the supplementary sheet. Easly doesn't calculate depreciation, private shares or the closing balance sheet - you or your accountant add these.

Frequently asked questions

Do I have to enclose my receipts with my tax return?

No, usually not. You enclose your annual financial statements or a statement of income, expenses, assets and liabilities. You keep the receipts for 10 years and submit them if the tax office asks for them.

How much can I pay into pillar 3a as a self-employed person?

If you don't belong to a pension fund, up to 20% of your net earned income, at most CHF 36'288 in 2026. If you belong to a pension fund through employment or on a voluntary basis, the lower maximum of CHF 7'258 applies.

Why do I get an AHV bill years later?

The compensation office issues its final settlement as soon as the tax authority reports your assessed income (Art. 23 AHVV). If your profit was higher than assumed for the provisional contributions, you pay the difference.

Does Easly fill in my tax return?

No. Easly provides the income statement, reports and all receipts as an export. You fill in the tax return yourself, using your canton's software, or your accountant does it for you.

Information as of: see above. Sources: Federal Act on Direct Federal Taxation (Art. 27, 28, 33 and 125 DBG, in German), Tax Harmonization Act (StHG, in German), Swiss Code of Obligations (Art. 957 and 958f CO), AHV Ordinance (Art. 23 AHVV, in German), FTA leaflet A 1995, Zurich Cantonal Tax Office (both in German). Forms, deadlines and practice vary from canton to canton. This article is not a substitute for tax or accounting advice.

Further reading