How treaties prevent double taxation
- Reduced withholding rates on cross-border FDAP income (often 0% to 15% vs 30% default)
- Foreign tax credit mechanism: home country credits US tax paid against home country tax on same income
- Tie-breaker residency rules to determine which country has primary taxing authority
- Permanent establishment definitions to limit business profits taxation
When double taxation could occur
- You become a US tax resident while still home-country resident (rare; one or the other usually applies)
- Your home country does not provide foreign tax credit (most do, especially treaty partners)
- You earn US-source income with limited or no treaty applicability (UAE, Brazil, others without treaties)
- You miss the treaty claim (Form W-8BEN-E not filed)
Practical prevention
- File Form W-8BEN-E with all US payers to claim treaty rates
- Track US tax paid (1042-S forms from payers, IRS receipts for Form 5472 add-on)
- Provide US tax payment evidence to home country CPA for foreign tax credit calculation
- If your country has no US treaty (UAE, Brazil), consult home country CPA about alternative relief