Typical Mistakes When Filing Your Online Tax Return

More and more cantons are introducing e-filing systems such as ZHprivateTax, VaudTax, or BE-Login. Online tax returns offer many benefits: less paperwork, automated calculations, and direct submission to the tax office. However, each year, many taxpayers make mistakes – often with financial consequences. This article highlights the most frequent pitfalls and gives tips on how to complete your online tax return correctly.

Mistake 1: Duplicate or Incorrect Entries

Many systems allow you to import data from the previous year. While convenient, this often leads to outdated or incorrect information being carried forward. Typical errors include old medical expenses or commuting allowances being reused even though they have changed.

Tip:
Carefully review each section before submitting. Delete outdated entries and replace them with the correct, current amounts.

Mistake 2: Entering Both Flat-Rate and Actual Expenses

A common error occurs when taxpayers enter both the flat-rate deduction for professional expenses and individual actual costs. This automatically triggers corrections by the tax office and may result in questions or reductions.

Tip:
Decide clearly between flat-rate and actual expenses. Check which option benefits you most – and stick to it consistently.

Mistake 3: Missing Supporting Documents in Digital Filing

Even if you submit your return online, the tax office still requires proof. Many forget to upload or send receipts, especially for medical expenses, donations, or training costs. Without them, deductions are often denied.

Tip:
Upload all relevant receipts as PDF or image files. Use the system’s upload function wherever available.

Mistake 4: Issues for Married Couples and Partnerships

For jointly taxed couples or registered partners, income and deductions are often misallocated. Typical errors include duplicate entries or forgetting to claim the second-earner deduction.

Tip:
Ensure income and deductions are distributed correctly between both partners. Don’t forget the second-earner deduction – up to CHF 14,100 under federal tax.

Mistake 5: Failing to Update Asset Information

Banks and brokers provide account and portfolio statements digitally. However, many taxpayers still enter figures from the previous year or forget to include new accounts. Cryptocurrencies are also frequently reported incorrectly.

Tip:
Use your bank’s tax statements or the official Federal Tax Administration (FTA) price list for cryptocurrencies. Report your full asset position as of December 31 accurately.

Mistake 6: Technical Problems and Lack of Final Review

Some online systems are not user-friendly. Errors occur when fields are skipped or entries are not saved properly. Submitting without a final review is particularly risky.

Tip:
Use the system’s built-in review functions. Most platforms flag incomplete or incorrect information. Also, perform your own plausibility check – do income, deductions, and assets add up correctly?

Conclusion: Care Pays Off – Even Digitally

The online tax return simplifies the process but requires just as much attention as the paper version. By carefully uploading receipts, choosing between flat-rate and actual expenses, and keeping all data up to date, you can avoid the most common mistakes. With one final thorough check before submitting, you’ll not only ensure accuracy but also build trust with the tax office.