W8 vs W9 Tax Forms: Which One Do You Need as an American Expat? 

W8 vs W9 Tax Forms: Which One Do You Need as an American Expat? 

Here’s reassuring news: most types of U.S. source income received by a foreign person are subject to U.S. tax of 30 percent, but if you’re a US citizen or resident alien, you’ll use Form W-9 and likely owe nothing in US taxes. 

The quick answer: Form W-9 is for US citizens, resident aliens, and US entities to provide their taxpayer identification number. Form W-8 is for nonresident aliens and foreign entities to certify their foreign status and claim reduced withholding rates from the default 30% rate. 

If you’re an American expat, determining which form you need comes down to one simple question: Are you a US person for tax purposes? The good news is that once you know your status, the choice becomes straightforward, and with the right tax benefits, you’ll likely end up owing zero US taxes. 

Many of our 23,000+ expat clients initially feel confused about which form applies to their situation. After helping Americans file over 71,000 returns while maintaining our 4.9-star average on TrustPilot, we’ve seen that most expats end up using Form W-9 and owe nothing thanks to the Foreign Earned Income Exclusion and Foreign Tax Credit

Which Form Should I Use: W8 or W9? 

The fundamental difference lies in who uses each form: 

Form W-9 (Request for Taxpayer Identification Number and Certification): 

  • Used by US citizens and resident aliens regardless of where they live 
  • Provides your taxpayer identification number (TIN) to payers for 1099 reporting 
  • No expiration date unless your information changes 
  • Not filed with the IRS – kept by the requesting party 

Form W-8 (Certificate of Foreign Status): 

  • Used by nonresident aliens and foreign entities 
  • Certifies foreign status and may claim treaty benefits to reduce the 30% withholding 
  • Expires after three years and must be renewed 
  • Can eliminate withholding on US-source income 

Critical point: If you’re a US citizen (even living abroad) or resident alien, you cannot use Form W-8. You must use Form W-9. 

Am I Considered a Resident Alien or a Nonresident Alien? 

Resident aliens always use Form W-9, never Form W-8. This distinction confuses many expats, but it’s simpler than you think. 

You’re considered a resident alien if you meet either of the following: 

  1. Green Card Test: You’re a lawful permanent resident at any time during the tax year 
  2. Substantial Presence Test: You’re physically present in the US for:  
    • 31 days in the current year, AND 
    • 183 days total using this formula: All days in the current year + 1/3 of days in the prior year + 1/6 of days in the year before that 

        Real-world example: Sarah, a US citizen, worked in New York for two years before moving to London in 2023. Even though she now lives abroad, she meets the substantial presence test for 2024 and must use Form W-9, not W-8. With the Foreign Earned Income Exclusion of $130,000 for 2025, she’ll likely owe zero US taxes. 

        Many banks incorrectly assume that only green card holders are resident aliens, but the substantial presence test often applies to long-term workers and students. 

        Do Only US Citizens Use Form W-9? 

        No, Form W-9 isn’t exclusively for US citizens. Several categories of people use W-9: 

        Who uses Form W-9: 

        • US citizens (including those living abroad) 
        • Lawful permanent residents (green card holders) 
        • Resident aliens who pass the substantial presence test 
        • US partnerships, corporations, and LLCs 
        • Domestic trusts 

        Who uses Form W-8: 

        • Nonresident aliens 
        • Foreign corporations 
        • Foreign partnerships 
        • Foreign trusts 
        Take Note

        Your physical location doesn’t determine which form you use. Your tax status does.

        Why Would Someone Need a W-8 Form? 

        Form W-8 serves two primary purposes: avoiding the default 30% withholding on US-source income and claiming treaty benefits for even lower rates. 

        Avoiding 30% Withholding 

        Without a properly completed W-8 form, payers must withhold 30% of US-source income from foreign persons. Common situations include: 

        • Interest from US bank accounts 
        • Dividends from US investments 
        • Rental income from US property 
        • Payments for services performed in the US 

        Claiming Treaty Benefits 

        Many tax treaties reduce or eliminate withholding rates for residents of treaty countries. For example, the US-UK treaty often reduces withholding on certain types of income to 15% or even 0%. 

        Take Note

        W-8 forms must be renewed every three years, unlike W-9 forms which remain valid indefinitely.

        What Situations Will I Encounter as an American Expat? 

        Scenario 1: US Citizen Working Abroad 

        • Situation: You’re a US citizen working for a foreign company that occasionally pays you for US-based projects.
        • Form Needed: W-9 (because you’re a US citizen)
        • Tax Result: No withholding on payments, and with Form 2555 for the FEIE, you’ll likely owe nothing to the IRS. 

        Scenario 2: Former Resident Now Abroad 

        • Situation: You lived in the US for three years, then moved to Germany. You still have US investments.
        • Status Check: If you don’t meet the substantial presence test for the current year, you’re likely a nonresident alien.
        • Form Needed: W-8BEN (for individuals) to claim treaty benefits and reduce withholding 

        Scenario 3: Foreign Spouse of a US Citizen 

        • Situation: You’re married to a US citizen but have never lived in the US.
        • Form Needed: Typically W-8BEN, unless you elect to be treated as a US resident for tax purposes 

        Scenario 4: Digital Nomad with US Clients 

        • Situation: You’re a US citizen providing services to US companies while traveling.
        • Form Needed: W-9 (citizenship doesn’t change based on location)
        • Tax Result: With the FEIE excluding up to $130,000 in 2025, most digital nomads owe zero US taxes
        Why Do I Have To Pay U.S. Taxes If I Live Abroad?

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        What Happens If I Use the Wrong Form? 

        Using the incorrect form creates complications, but they’re fixable: 

        Using W-8 when you should use W-9: 

        • May trigger FBAR or FATCA compliance questions 
        • Could result in incorrect tax withholding 
        • Banks may apply the wrong reporting procedures 

        Using W-9 when you should use W-8: 

        • Results in backup withholding at 24% if information is missing or incorrect 
        • Creates unnecessary complications with foreign tax reporting 

        The good news is that these issues can be corrected by submitting the proper form and, if necessary, working with a qualified expat tax professional. 

        What Are the Important Deadlines? 

        W-9 Forms: 

        • No specific deadline – typically requested when establishing business relationships 
        • Valid indefinitely unless your information changes 

        W-8 Forms: 

        • Must be provided before receiving income to avoid maximum withholding 
        • Valid for the year signed plus three full calendar years 
        • Must notify the payer within 30 days of any status changes 

        How Can This Impact My Overall Expat Tax Situation? 

        These forms are just one piece of your expat tax strategy. Here’s the bigger picture that should give you confidence: 

        Most American expats end up owing zero US taxes thanks to two main protections: 

        1. Foreign Earned Income Exclusion: Exclude up to $130,000 of foreign-earned income for 2025 
        2. Foreign Tax Credit: Dollar-for-dollar credit for foreign taxes paid 

          Whether using W-9 or W-8 forms, you’ll likely qualify for significant tax benefits that reduce or eliminate your US tax liability. 

          What Should I Do Next? 

          1. Determine your tax status: Are you a US citizen, resident alien, or nonresident alien? 
          2. Use the correct form: W-9 for US persons, W-8 for foreign persons 
          3. Plan your expat tax strategy: Consider which benefits (FEIE or Foreign Tax Credit) work best for your situation 
          4. Keep copies: Maintain records of submitted forms for your tax files 

              Whether you’re dealing with W-8 vs W-9 questions or planning your broader expat tax strategy, we’ll match you with the right accountant based on your unique situation. You’ll have direct, one-on-one access with transparent, flat-fee pricing backed by our Make It Right guarantee. 

              No matter how late, messy, or complex your return may be, we can help. Knowing that your taxes were done right will give you peace of mind. 

              Ready to get your expat taxes sorted? Contact us, and one of our customer champions will gladly help. If you need specific advice on your tax situation, click below to get a consultation with one of our expat tax experts.

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              This article is for informational purposes only and should not be considered tax advice. Tax situations vary, and you should consult with a qualified tax professional for advice specific to your circumstances.