Which Documents Do I Need for the Tax Return?

A complete and well-prepared tax return not only saves time but also ensures that all possible deductions are claimed. Every year, many taxpayers ask: Which documents do I need to submit?

This article provides an overview of the key documents required for a tax return in Switzerland – from salary statements to insurance certificates.

Basic Documents

Personal Information

• Last definitive tax assessment
• Tax return form or access to your canton’s online portal

Income

• Salary statement from employer
• Proof of additional income, fees, or self-employment activities
• Certificates of pensions, allowances, or daily benefits (AHV, IV, ALV, sickness benefits)

Assets

• Bank and postal account statements (as of December 31)
• Securities holdings (stocks, funds, bonds)
• Life insurance with surrender value
• Vehicle registrations and estimated vehicle value

Real Estate and Property

• Tax value and imputed rental value of property
• Proof of mortgage interest (bank statements)
• Maintenance and renovation costs (receipts or flat-rate deduction)
• Energy costs and proof of energy renovations
• Utility statements for rented properties

Insurance and Retirement Savings

• Health insurance and other insurance:
  • Proof of paid premiums (health insurance, household, liability, life insurance)
• Retirement savings:
  • Proof of Pillar 3a contributions
  • Contributions to pension fund (voluntary Pillar 2 buy-ins)

Deductible Expenses

Professional Expenses

• Travel costs (public transport subscription, mileage for car use)
• Office supplies (computer, professional literature, tools)
• Meal allowances (e.g., working away from home)
• Home office costs or rent for a separate office

Children and Family

• Receipts for childcare costs (nursery, daycare, after-school care)
• Proof of children’s education (studies, apprenticeships)
• Family allowances and child benefits

Other Deductions

• Medical and accident costs not covered by insurance
• Donation receipts for charitable organizations
• Alimony payments (spousal or child support)

Special Situations

Self-Employed

• Business accounting (balance sheet, profit & loss, receipts)
• Separation of private and business expenses

Foreign Assets

• Proof of foreign property (imputed rental value, tax statements)
• Proof of interest and dividends from foreign banks
• Proof of foreign tax payments (for double taxation agreements)

Practical Examples

Example 1: Employee in Zurich

Needs: salary statement, bank statements, health insurance receipts, Pillar 3a proof, and public transport subscription.

Example 2: Family in Bern with Property

Additionally: mortgage interest certificate, renovation receipts, and childcare cost receipts.

Example 3: Self-Employed Entrepreneur in Basel

Additionally: business accounting, securities holdings, insurance certificates, and retirement contributions.

Common Mistakes and Tips

Common Mistakes

• Not including account statements as of December 31
• Forgetting insurance premiums or medical costs
• Failing to keep donation receipts

Tips

• Start a document folder at the beginning of the year
• Use online checklists from cantonal tax authorities
• Archive all documents digitally
• Clarify open questions with the tax office early

Conclusion

A correct tax return requires numerous documents – from income statements to insurance certificates. Collecting and submitting all documents in an organized manner ensures that all possible deductions are claimed and avoids follow-up questions from the tax office.