How the Tax Return Works in Switzerland Step by Step

The annual tax return is a necessary task for many – but with the right preparation and a clear process, it can be done efficiently. While procedures vary by canton in Switzerland, the basic structure remains the same everywhere.

In this article, we show you step by step how the tax return works in Switzerland – from preparation to submission.

Step 1: Gather documents

Before you start your tax return, you should have all necessary documents ready:

• Salary statements and pension certificates
• Bank and securities account statements as of 31 December
• Insurance certificates (health insurance, Pillar 3a, life insurance)
• Mortgage interest certificates and property documents
• Receipts for professional expenses, medical costs, childcare, etc.
• Securities lists and documentation for cryptocurrencies or digital assets
• Confirmation of retroactive Pillar 3a contributions (new from 2026)

Step 2: Access the tax return

Electronic tax return

All cantons now offer online portals or software for completing and submitting the tax return digitally. In most cantons, fully electronic submission including attachments is possible – a paper signature is no longer required.

Paper form

Some cantons still send tax forms by post that can be completed by hand. However, this option is becoming increasingly rare.

Step 3: Enter personal information

The first part of the tax return covers personal data:

• Marital status (single, married, registered partnership, divorced, widowed)
• Children and dependants
• Religious affiliation (for church tax)
• Housing situation (rental, ownership)

Step 4: Declare income

All income must be declared in full:

• Employment income (salary, secondary employment, self-employment)
• Capital income (interest, dividends, securities income)
• Pensions (AHV/OASI, IV/DI, occupational pension)
• Other income (rental income, maintenance payments, lottery winnings over CHF 1 million)

Important: Foreign income must also be declared, even if already taxed abroad. It is used at minimum for rate determination purposes.

Step 5: Declare assets

Assets include:

• Bank and postal account balances
• Securities, shares, funds, bonds
• Cryptocurrencies and digital assets (market value as of 31 December)
• Real estate (with tax value and imputed rental value)
• Vehicles, life insurance policies with surrender value
• Cash holdings and precious metals

Step 6: Claim deductions

Deductions reduce taxable income. These include:

• Professional expenses (commuting costs, work equipment, additional meal costs)
• Health insurance premiums and medical costs (above the deductible threshold, typically 5% of net income)
• Pillar 3a contributions (max. CHF 7,258 with pension fund, max. CHF 36,288 without, as of 2025/2026)
• Retroactive Pillar 3a contributions (new from 2026 for contribution gaps from 2025)
• Voluntary pension fund purchases (Pillar 2)
• Debt interest (mortgages, loans)
• Maintenance and childcare costs
• Donations to charitable organisations (generally up to 20% of net income)
• Training and education costs (max. CHF 12,000 per year)

Step 7: Review and submit

Before submission, be sure to check:

• Do all entries match the supporting documents?
• Have all relevant deductions been entered?
• Have all documents been attached or uploaded?

Submission can be done either:

• Online via the cantonal portal (recommended) or
• By post to the relevant tax office.

Deadline: In most cantons, by 31 March of the following year. Exceptions include Geneva and Vaud (28 February), Valais (15 March) or Ticino (30 April). Extensions can usually be requested if needed.

Step 8: Await the tax assessment

After reviewing the tax return, you will receive the final tax assessment.

• If it contains errors, you can file an objection within 30 days.
• If the details are correct, you pay the determined taxes: direct federal tax plus cantonal and municipal taxes.

Tip: Review the assessment carefully. Deductions are frequently not accepted or only partially accepted by the tax office – in such cases, filing an objection is worthwhile.

Practical examples

Example 1: Employee in Zurich

Uses the Canton of Zurich’s online tax return, enters salary income and Pillar 3a contribution, and claims commuting deductions. Submission is fully digital by 31 March.

Example 2: Family with property in Bern

Declares income and assets, enters imputed rental value, mortgage interest and maintenance costs. Childcare costs are claimed as an additional deduction.

Example 3: Self-employed businesswoman in Basel

Submits business accounts (balance sheet and income statement) in addition to the personal tax return. Deductions for business vehicle and office space are included.

Common mistakes and tips

Common mistakes

• Forgetting deductions (e.g. Pillar 3a, medical costs, donations, training costs)
• Incorrect information on securities or property
• Not declaring cryptocurrencies (considered tax evasion)
• Missing the deadline and risking reminder fees
• Not reviewing the assessment and accepting it incorrectly

Tips

• Collect and organise documents throughout the year – ideally digitally
• Note the submission deadline in your calendar and request an extension in good time if needed
• Ensure all account statements as of 31 December are available
• For complex cases (e.g. self-employment, foreign property, cryptocurrencies) seek professional help
• Review the final assessment within the 30-day objection period

Conclusion

The tax return in Switzerland follows a clear process – from gathering documents to declaring income and assets, claiming deductions and submitting. Those who proceed in a structured manner, observe all deadlines and critically review the assessment can avoid unnecessary mistakes and potentially save on taxes.