Before You Start
- Understand your tax residency status and which countries you invest in
- Know the types of investment income you receive (dividends, interest, capital gains)
- Have access to your broker account(s) (e.g., DEGIRO, Interactive Brokers)
- Be able to download your annual tax reports and dividend statements
- Check if your country has a Double Taxation Agreement (DTA) with the country where your investments are located
Time needed: 30–60 minutes for initial setup, plus time for annual tax filing
What you'll need: Broker account login, tax ID number, access to official tax forms, PDF reader
Double taxation is a frustrating reality for many European investors who hold assets across borders. In 2026, the landscape is shaped by updated treaties, evolving broker support, and stricter tax reporting. This guide will walk you through step-by-step tactics to avoid paying tax twice on your investment income—so you keep more of your returns.
Step 1: Identify Where Double Taxation Applies
What to do: Review your portfolio and list all countries where your investments are domiciled. For each, identify the type of income (e.g., dividends from a US ETF, interest from a French bond, etc.).
Why it matters: Double taxation typically occurs when both the source country (where the investment is located) and your country of tax residence levy taxes on the same income. For example, as a German resident holding US stocks, you may face 15% US withholding tax on dividends, plus German income tax on the same dividends.
What can go wrong: If you don’t know the country of domicile for each investment, you can’t apply the right treaty benefits or claim relief. Many European investors assume their Irish-domiciled ETFs (like CSPX) face US withholding, when in reality they do not.
Pro Tip
For ETFs, check the Key Investor Information Document (KIID) or your broker’s asset details to confirm the fund domicile. Irish-domiciled ETFs (e.g., CSPX) often offer tax advantages for European investors.
Step 2: Check Double Taxation Agreements (DTAs)
What to do: Visit your national tax authority’s website or the OECD DTA database and look up the agreement between your country of residence and each source country. Focus on the maximum withholding rates for dividends, interest, and royalties.
Why it matters: DTAs limit how much tax the source country can withhold and allow you to claim a credit or refund for tax already paid abroad. For example, most EU-US DTAs cap US dividend withholding at 15% for European residents (with proper documentation).
What can go wrong: If you don’t claim treaty benefits, you may be overcharged—such as paying the default 30% US withholding instead of the 15% treaty rate.
Pro Tip
Keep a spreadsheet of your investments, their domiciles, and the relevant DTA withholding rates. This will make tax claim paperwork much easier each year.
Step 3: Ensure Your Broker Applies Treaty Rates
What to do: Log in to your broker account and check your tax residency status and documentation. For example:
- In DEGIRO: Go to Profile → Tax Residency and ensure your country is correct. For US securities, DEGIRO will prompt you to complete a W-8BEN form online.
- In Interactive Brokers: Go to Account Settings → Tax Forms and fill in the W-8BEN electronically if you hold US assets. For other countries, check for local tax forms (e.g., French 5000/5001 for French stocks).
Why it matters: Brokers use these forms to apply the correct withholding rate at source. Missing or incorrect forms mean you’ll pay the default (higher) rate, losing money unnecessarily.
What can go wrong: Some brokers (e.g., Trade Republic) do not support all tax forms for every market. You may need to claim refunds directly with foreign tax authorities if the broker cannot process the forms.
Pro Tip
Set a reminder to review and update your tax residency documents every January. This ensures you benefit from treaty rates each tax year.
Step 4: Gather Documentation for Tax Claims
What to do: Download your annual tax reports and dividend statements from your broker. For DEGIRO: Documents → Annual → Tax Statement. For Interactive Brokers: Reports → Tax → Tax Forms.
You will usually need:
- Dividend statements showing gross and net amounts
- Proof of foreign tax withheld (often on the dividend statement)
- Your broker’s annual tax report
- Your tax identification number (TIN)
Why it matters: These documents are required to claim a foreign tax credit in your home country, or to request a refund from the source country.
What can go wrong: Missing or incomplete documentation is the #1 reason for rejected tax claims. Always download and save these files at year-end, as brokers may not keep them available indefinitely.
Step 5: Claim Tax Relief in Your Home Country
What to do: When filing your annual tax return, declare your foreign investment income and the amount of foreign tax already withheld. In most EU countries, there is a specific section for “foreign-sourced income” and “foreign tax credit.”
- In Germany: Use Anlage KAP and Anlage AUS forms.
- In France: Use Form 2047 for foreign income and credit d’impôt calculation.
- In Italy: Use Quadro RM.
- In Spain: Use Modelo 100, Annex D6.
EUR Example: Suppose you receive €1,000 in US dividends via Interactive Brokers. The US withholds 15% (€150) due to the DTA. If your home country (say, Germany) taxes dividends at 26.375%, you’ll owe €263.75 total—minus the €150 already paid. You only pay the difference (€113.75) to the German tax office.
Why it matters: Correctly claiming the foreign tax credit ensures you don’t pay tax twice on the same income.
What can go wrong: If you forget to declare foreign tax paid, you’ll be taxed fully in your home country and lose out on the credit.
Pro Tip
Some countries (e.g., Germany, France) allow you to carry forward unused foreign tax credits. If you can’t use the full credit this year, check if you can apply it next year.
Step 6: (Optional) Request a Refund from the Source Country
What to do: If your broker did not apply the correct treaty rate (e.g., withheld 30% US tax instead of 15%), you can apply directly to the source country’s tax authority for a refund.
- For US stocks: File IRS Form 1042-S and Form 8802 (for a Certificate of Residency), then Form 1040NR or use a reclaim service.
- For French stocks: Use Form 5000 and 5001, often requiring certification by your home tax office.
Why it matters: This is your last resort to recover excess withholding. The process can be slow (6–18 months) and may require translation or notarisation.
What can go wrong: Incomplete forms, missing residency certificates, or late filings can lead to denied refunds.
Pro Tip
Consider using a professional reclaim service if the refund is significant (over €500). For small amounts, weigh the time and paperwork against the benefit.
Common Mistakes to Avoid
- Not updating your tax residency with your broker after moving countries
- Assuming all ETFs face the same withholding—Irish-domiciled funds like CSPX often have lower drag (learn more)
- Failing to download and save annual tax reports
- Missing the deadline for foreign tax credit or refund claims
- Overlooking local capital gains tax rules—these are rarely covered by DTAs
- Not reading up on dividend tax minimization strategies (see our tips)
Next Steps
- Map out your portfolio’s country exposures and DTA rates
- Check your broker’s tax forms and update your residency information
- Download all annual reports and keep them organized
- Plan for tax season: know which forms you’ll need and set reminders for deadlines
- If you’re new to cross-border investing, consider starting with tax-efficient ETFs or bond funds (see our EUR guide)
Disclaimer: This article is for educational purposes only and does not constitute financial advice. Always do your own research and consider consulting a qualified financial advisor before making investment decisions.