US Expat Taxes – A Guide For Americans living in or moving to Belgium

Belgium holds an enduring appeal as a destination for Americans moving overseas, thanks to its culture, charming cities, and easy access to the rest of Europe. If you’re living in or planning to move to Belgium as an American expat, understanding your tax obligations is essential to avoid costly mistakes. In this article, we provide an overview of what you need to know about US expat taxes for Americans living in or moving to Belgium, from filing requirements and tax treaties to avoiding double taxation.

US tax obligations while living in Belgium

All US citizens and green card holders must report their worldwide income to the IRS. Living abroad doesn’t negate that responsibility.

If your income exceeds minimum thresholds, you must file a return using Form 1040. Expats often owe no US tax because of available exclusions and credits. Minimum thresholds are $15,750 for single filers for the 2025 tax year, and just $400 of self-employment income, or just $5 if you’re married filing separately (e.g. many expats married to non-US citizens).

Filing Form 1040 from Belgium

All expats must file Form 1040 each year. The standard deadline is April 15, but you get an automatic two-month extension to June 15, if you are outside of the US on April 15th.

If you need more time, file Form 4868 for an extension to October 15. You must still pay any taxes owed by April 15 to avoid interest and penalties.

Foreign account and asset reporting – FBAR and FATCA

Americans in Belgium often have foreign bank and investment accounts, which may trigger additional reporting.

• FBAR (FinCEN Form 114) – If your foreign accounts total more than $10,000 at any point in the year, you must file an FBAR. This includes personal accounts, business accounts, and joint accounts. File electronically by April 15 (extended to October 15 automatically).
  
• FATCA (Form 8938) – If your foreign accounts and financial assets exceed $50,000 (single) or $100,000 (married filing jointly) at year-end, file Form 8938. However, if you live abroad and meet certain conditions, the thresholds are $200,000 (single) or $400,000 (married filing jointly) at year-end
  

Failing to report foreign accounts can result in large penalties.

If you have certain types of pooled foreign investments such as mutual funds or ETFs, the IRS classifies these types of assets as PFICs. If you have PFICs, you have to file Form 8621 per investment, and you may incur an additional US tax bill, so it’s best to avoid these types of investments entirely.

If you own more than 10% of a foreign corporation meanwhile, you’ll also have additional reporting requirements, including Form 5471, and again there can be additional US taxation implications under GILTI rules. 

Seek advice from a US expat tax planning specialist before incorporating or investing overseas. We can help with that, so get in touch to discuss your options.

How to avoid double taxation

There are three main ways that expats in Belgium can reduce or eliminate their US tax liability:

• Foreign Earned Income Exclusion (FEIE) – You can exclude up to $130,000 in 2025 by using Form 2555. To qualify, pass either the physical presence test (330 full days in a 12-month period) or the bona fide residence test.
  
• Foreign Housing Exclusion – If you qualify for FEIE, you may also exclude some of your housing costs above a base threshold. This applies to rent and certain utilities, not mortgage interest.
  
• Foreign Tax Credit (FTC) – If you pay income tax in Belgium, you can use Form 1116 to claim a dollar-for-dollar credit on your US taxes. You can carry forward unused credits for 10 years.

Most expats choose either FEIE or the FTC based on their income levels and how much foreign tax they paid. Claiming the FTC also makes claiming the refundable Child Tax Credit and making contributions to IRAs simpler.

Using the US – Belgium tax treaty

The US and Belgium have a tax treaty that aims to prevent double taxation. It covers income from wages, pensions, interest, and other sources.

However, the treaty contains a “saving clause” that allows the US to tax its citizens even when the treaty says otherwise.

To claim benefits under the treaty, such as pension income or certain tax-free employer reimbursements, you may need to file Form 8833 with your US tax return.

Social security – how the totalization agreement works

The US and Belgium signed a totalization agreement that prevents you from paying social security tax to both countries for the same work.

• If you work for a Belgian employer, you pay into Belgium’s system.
  
• If you’re on a short-term assignment from a US employer, you may stay under US social security.

This agreement also helps you combine credits for future retirement benefits if you split your working life between both countries.

What to do if you’re behind on US taxes

Many Americans living in Belgium haven’t filed US tax returns for years because they weren’t aware that they have to. If the IRS hasn’t contacted you yet, there’s a way to catch up penalty-free through the Streamlined Filing Compliance Procedures.

You must file:

• The last three years of tax returns
  
• The last six years of FBARs
  
• A signed statement confirming your failure to file was non-willful

If you qualify, it’s the safest way to get compliant. Seek advice from an expat tax specialist to find out more.

Belgian tax basics for US expats

Although US expats need to focus primarily on their IRS obligations, if you live in Belgium, you’ll need to understand the Belgian tax system, too.

Belgium determines tax residency based on several factors. You are considered a resident for tax purposes if Belgium is your primary home, if your immediate family resides there, or if you spend more than 183 days in the country during the year. Once considered a tax resident, you are subject to Belgian income tax on your worldwide income. Non-residents, by contrast, are only taxed on income sourced within Belgium.

Belgian income tax rates in 2024

Belgium has a progressive tax system, with rates ranging from 25% to 50%.

• Up to €15,820 – 25%
  
• €15,820 to €27,920 – 40%
  
• €27,920 to €48,320 – 45%
  
• Over €48,320 – 50%

These national rates apply before municipal surcharges, which add another 2.5% to 9%, depending on your place of residence. Most municipalities charge around 7%, making Belgium one of the highest-tax countries in Europe.

Belgian tax deadlines

The Belgian tax year aligns with the calendar year. Employees typically have taxes withheld directly from their paychecks, but an annual return is still required. If you file a paper return, the deadline is June 30. For those filing electronically, the deadline is usually extended to July 15. Self-employed individuals, landlords, and those with foreign income must be especially diligent about reporting all sources of income.

Belgium foreign reporting requirements

Belgium also requires disclosure of foreign financial assets. If you are a Belgian tax resident and you hold foreign bank accounts, you must register them with the National Bank of Belgium. Additionally, you must report these accounts each year on your tax return. 

Belgian residents must declare:

• Foreign bank accounts
  
• Overseas real estate
  
• Certain foreign investments
  
• Life insurance held abroad

High-value accounts may be subject to a 0.15% tax on securities.

For Americans used to a simpler or lower-tax environment, the Belgian system can feel overwhelming at first. However, once you understand the key rules—residency, progressive income tax, mandatory declarations, and municipal surcharges—you can manage your obligations effectively. For most US expats, the Belgian tax you pay will more than cover any US liability, especially when using the foreign tax credit.

Real-world expat example

Michael is a US citizen living in Antwerp. He earns €95,000 working for a Belgian company. Here’s what he does each year:

• Files Form 1040 with the IRS by June 15
  
• Files Form 114 (FBAR) for his Belgian bank accounts
  
• Files Form 8938 because his foreign assets exceed $200,000
  
• Claims the foreign tax credit using Form 1116 to nullify his US tax liability, and also claims the refundable Child Tax Credit
  
• Pays Belgian income tax at 50% plus 7% local tax
  
• Files his Belgian return online by July 15

His Belgian tax liability exceeds what he’d owe the US, so with proper filing, he owes nothing to the IRS.

US and Belgian tax deadlines at a glance

Filing requirement	US deadline	Belgian deadline
Form 1040	June 15 (extension to Oct 15)	June 30 (paper), July 15 (online)
FBAR (Form 114)	April 15 (extended to Oct 15)	Not required in Belgium
FATCA (Form 8938)	April 15 (extended to Oct 15)	Not required in Belgium
Belgian tax return	Not applicable	See above

ASA – Always Seek Advice

If you’re an American living in Belgium, the IRS still expects a full tax return every year. Fortunately, provisions like the foreign earned income exclusion, foreign tax credit, and the US – Belgium tax treaty can eliminate your US tax bill entirely.

 Understanding both countries’ systems helps you avoid penalties and file with confidence. Stay on top of FBAR and FATCA rules, meet deadlines, and get caught up if needed using the Streamlined Procedures. Most importantly though, always seek advice from a US expat tax specialist to ensure you stay compliance and tax optimized.