U.S. taxes for Americans in Belgium: what to file, and how to catch up.
Brussels draws Americans working for international companies, institutions and law firms, and all of them still file a U.S. return every year. Belgian tax usually covers the U.S. bill on wages. The details to get right are pension savings, group insurance and Belgian funds. Most people who fell behind can catch up under the Streamlined procedures, with no penalty if they qualify.
Sound familiar?
- You moved to Brussels for a job and stayed.
- Your employer offers group insurance (groepsverzekering or assurance de groupe).
- You save in pension savings (pensioensparen) for the Belgian tax break.
- Your Belgian bank asked about your U.S. citizenship.
How does the IRS treat Belgian pensions and savings?
Every one of these goes on your FBAR. What differs is how the IRS taxes them.
| Account | U.S. treatment | |
|---|---|---|
| Belgian state pension | Under the treaty, only Belgium can tax it, even for U.S. citizens. | Usually fine |
| Group insurance (employer pension) | If you work for a Belgian employer, the treaty can keep your contributions, and what the plan builds up, off your U.S. return while you work there, within limits. | Mostly friendly |
| Pension savings (pensioensparen) | Tax-favored in Belgium only. Growth may be taxable for the U.S., and some plans hold PFICs. | Check first |
| Belgian funds | Usually PFICs (Form 8621), with complex reporting and tax rules. | Watch out |
| Savings accounts | Interest is taxable for the U.S., even the part that’s tax-free in Belgium, and the accounts count toward your FBAR total. | Taxable |
| Securities account tax | Belgium’s annual tax on large securities accounts is a tax on assets, not income, so it doesn’t reduce your U.S. tax. | Plan ahead |
Which Belgian investments are PFICs?
Belgian funds and SICAVs, the European ETFs Belgian banks and brokers sell, and the funds inside many pension savings plans and branch 23 insurance products. For U.S. tax they’re passive foreign investment companies, or PFICs.
- Each fund needs its own Form 8621 in most years, and gains can be taxed at the top U.S. rate plus an interest charge, unless an election was made in time.
- A pension savings plan invested in a fund is usually the first PFIC Americans in Belgium have, often without knowing it.
- Not PFICs: shares of individual companies, Belgian government bonds, and savings accounts.
What does the U.S.–Belgium tax treaty actually say?
The current treaty was signed in 2006 and took effect in 2008. For Americans living in Belgium, these parts matter most:
- The saving clause. The U.S. can tax its citizens as if the treaty didn’t exist, except for the provisions the treaty lists.
- Employer pensions. A U.S. citizen working for a Belgian employer can keep contributions to group insurance, and its growth, off the U.S. return, within the limits for a similar U.S. plan.
- Social security. The Belgian state pension is taxed only by Belgium, even for U.S. citizens, and U.S. Social Security only by the U.S.
- Relief from double tax. The U.S. gives a credit for Belgian income tax, with the municipal surcharge, on the same income.
Social security contributions are covered by a separate U.S.–Belgium agreement, which generally means you pay into one system, not both. Read the U.S.–Belgium tax treaty on IRS.gov.
When are Belgian and U.S. taxes due?
Both tax years run January to December, so each Belgian year lines up with one U.S. return. Your tax assessment (avertissement-extrait de rôle / aanslagbiljet) gives most of what the U.S. return needs.
| Belgium | United States | |
|---|---|---|
| Tax year | January to December | January to December |
| Annual return | Around mid-July online, earlier on paper; later through an accountant | April 15, moved to June 15 automatically when you live abroad, or October 15 with an extension |
| Paying the tax | Withheld from your salary, with any balance due after the assessment | April 15, even if you file later |
| Foreign accounts | Declared on the Belgian return and to the central register | The FBAR, due October 15, filed online |
Foreign tax credit or exclusion: which wins in Belgium?
Usually the foreign tax credit. Belgian income tax reaches 50%, plus the municipal surcharge, so Belgian tax on a salary is normally more than the U.S. tax on it, and the unused credit carries forward for up to 10 years.
- Staff of EU institutions are different. Their salaries are taxed by the EU, not Belgium. Whether that tax counts toward the U.S. credit, or the exclusion works better, depends on the details, so we look at it case by case.
- Families with children can get the refundable part of the U.S. child tax credit, up to $1,700 per child for 2025, by using the credit.
- Savings that are tax-free in Belgium have no Belgian tax to credit, so the U.S. tax on that interest is paid in full.
We run your returns both ways before choosing. How we compare the exclusion and the credit.
A worked example: a manager in Brussels
Sophie works for an international company in Brussels on €90,000 a year. Her employer pays into group insurance, she saves in a pension savings plan invested in a fund, and she keeps a regulated savings account. She hasn’t filed a U.S. return since moving in 2016.
| Item | How it’s handled |
|---|---|
| Salary | Belgian tax is higher than the U.S. tax on it, so with the foreign tax credit her U.S. tax on it is $0. |
| Group insurance | Under the treaty, her employer’s contributions and the growth stay off her U.S. return while she works there, within U.S. limits. |
| Pension savings fund | A PFIC: a Form 8621 in each year filed, and the growth could be taxable. |
| Savings account | The interest goes on her U.S. return, including the part that’s tax-free in Belgium. |
| Catching up | Three years of returns and six FBARs under the Streamlined procedures, with no penalty if she qualifies. |
Catching up from Belgium
Most Americans in Belgium who fell behind without meaning to can catch up under the Streamlined Foreign Offshore Procedures: three years of returns, six years of FBARs and, if you qualify, no penalties. If only FBARs are missing, or you’ve moved back to the U.S., another route may fit better. See every IRS catch-up option for expats, compared.
Common questions
Do I pay U.S. Social Security tax in Belgium?
Generally not if you pay into the Belgian system. The U.S.-Belgium totalization agreement prevents paying into both systems for the same work in most cases.
Will the U.S. tax my U.S. Social Security in Belgium?
The U.S. taxes it as usual. Under the treaty, Belgium can’t.
Should I sell my Belgian funds?
Maybe, but not before getting advice. Selling has tax consequences in both countries. We’ll show you the U.S. cost of keeping versus selling.
Is my group insurance taxed by the U.S.?
Generally not while you work for a Belgian employer. Under the treaty, contributions and growth stay off your U.S. return, within the limits for a similar U.S. plan.
I work for an EU institution. Is my U.S. return different?
Often, yes. Your salary is taxed by the EU rather than Belgium, which changes how the credit and the exclusion work. We look at it case by case.
Is my Belgian state pension taxed by the U.S.?
No. Under the treaty, only Belgium can tax it, even for U.S. citizens.
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