Belgium Inbound Tax: 35% Free After €70k

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As of January 2025, Belgium’s inbound-taxpayer regime prices you in at a little more than €70,000 of qualifying gross pay. At the Federal Reserve’s 28 August 2026 euro rate of $1.1598, that floor is about $81,200. Clear it, and your Belgian employer can add a tax-free “costs proper to the employer” allowance of up to 35% of that gross — with the old €90,000 yearly cap gone. Miss the floor, miss the three-month filing window, or treat this as a US tax holiday, and the Belgian cut evaporates while Form 1040 still taxes worldwide income.

This guide is for operators taking a Belgian employment contract or a qualifying director seat — US citizens and green-card holders recruited from abroad or seconded inside a multinational group. Families should model school-fee reimbursements and the 150-kilometer lookback before a spouse’s remote job looks like Belgian-source work. Researchers get a parallel track with no €70,000 floor if they clear the STEM and 80% R&D tests. Retirees and independent contractors should stop early: this is a payroll regime, not a pensionado or freelancer visa.

Belgium’s inbound cut sits next to other European inbound packages, including Spain’s Beckham-style path on the Spain 24% Beckham law guide. For the US overlay — FEIE, foreign tax credit, FBAR, and Form 8938 — use the Expat Tax & Finance hub before you sign the Belgian offer letter.

What Belgium actually changed in the inbound regime

Belgium replaced the old foreign-executive circular with statutory special regimes on 1 January 2022: inbound taxpayers (often labelled BBIB/STRIT) and inbound researchers (BBIO/STRIR). The Law of 18 December 2025, published in the Belgian Official Gazette on 30 December 2025, then rewired the numbers with retroactive effect from 1 January 2025.

As of that law, three tax knobs moved together. The inbound-taxpayer salary floor dropped from more than €75,000 to more than €70,000. The maximum tax-free reimbursement of costs proper to the employer rose from 30% to 35% of gross remuneration. The €90,000 annual cap on that reimbursement was repealed for pay granted from 1 January 2025.

FPS Finance circular 2026/C/51, dated 1 April 2026, told employers how to apply the retroactivity. People already on the regime can take the richer costs allowance from 1 January 2025. People who started Belgian employment between 1 January 2025 and 9 January 2026 with pay between €70,000 and €75,000 got a one-time late-application path through 9 April 2026. Contract addenda that lock in 35% (and, if you choose, a lower taxable salary that still clears €70,000) had to be in place within three months of the circular — by 1 July 2026.

Data note: salary floors, cost percentages, and social-security mismatch were checked against the 18 December 2025 law, circular 2026/C/51, and firm write-ups of FPS Finance and ONSS positions as of September 2026. Payroll teams should confirm the current ONSS circular before the next payslip run.

Who qualifies, and who is out

You must be an employee or a qualifying company director recruited from abroad by a Belgian company, a Belgian establishment of a foreign company, or a qualifying non-profit — or seconded by a foreign group company into one of those Belgian hosts. Nationality does not matter. Belgian passport holders can qualify if they truly lived and worked outside the 150-kilometer ring for the lookback.

For the 60 months before the Belgian start date you must not have been a Belgian tax resident, must not have lived within 150 kilometers of the Belgian border, and must not have been taxed as a Belgian non-resident on professional income. That 150-kilometer ring knocks out a large share of people commuting from the southern Netherlands, western Germany, Luxembourg, and northern France.

The employer — not you — files the electronic application with FPS Finance within three months of the start date. The administration generally has three months to decide. Approval, if granted, runs from the Belgian start date. Miss the window and the regime is lost unless you later prove another full 60-month absence and start over.

Duration is five years, with one three-year extension if the employer files again within three months after year five. Drop below the €70,000 inbound-taxpayer floor in any year and the regime stops. Researchers skip the salary floor but must spend at least 80% of working time on qualifying R&D and hold a PhD or a STEM master’s, or show at least ten years of relevant experience. Directors are out of the researcher track.

Do I still owe US tax if Belgium makes 35% tax-free?

Yes. A US citizen or green-card holder files Form 1040 on worldwide income even when Belgium treats part of the package as costs proper to the employer. The Belgian exemption does not rewrite Internal Revenue Code section 61, and it does not by itself create a foreign tax credit on the untaxed slice.

As of tax year 2026, the foreign earned income exclusion on Form 2555 is $132,900, per IRS Revenue Procedure 2025-32 and the 9 October 2025 IRS newsroom release. That exclusion can zero federal income tax on a large slice of Belgian wages if you pass the tax-home test plus bona fide residence or 330-day physical presence. It does not reduce US Social Security tax if you remain on a US payroll, and it does not create a credit for Belgian tax you never paid.

The 35% Belgian allowance is the trap for people who default to the foreign tax credit. Form 1116 only credits income tax paid or accrued to Belgium. If 35% of a large package is never subjected to Belgian income tax, that slice produces no Belgian tax and no US credit. High earners often run FEIE on earned income and Form 1116 on residual Belgian-taxed amounts, or they skip FEIE and live on credit — but only after they model the untaxed allowance. The mechanics live on FEIE vs foreign tax credit; do not copy a colleague’s election without rerunning the 35% case.

Self-employed US persons generally cannot use this regime at all. If you are on a US LLC taxed as a disregarded entity while physically working in Belgium, you are in Belgian social-security and PE analysis, not STRIT. Keep a US brokerage such as Charles Schwab for dollar assets so Belgian-domiciled funds do not drag you into PFIC filings on top of the payroll file.

How the 35% costs allowance actually works

The 35% is not a 35-point cut in the Belgian statutory rate. It is a cap on recurring extra-territorial costs the employer may pay or reimburse tax-free because you were recruited or seconded into Belgium. KPMG’s 2026 regime leaflet is explicit: those costs are paid in addition to gross remuneration, and the €70,000 floor is measured on that gross before social-security deductions, including vacation pay, 13th month, and benefits in kind, but excluding severance, the 35% costs themselves, and a short list of social benefits.

That sequencing matters in the offer letter. If the letter quotes one “total cost to company” number, ask payroll to split taxable gross, ONSS base, and costs proper to the employer on separate lines. If they compress 35% inside a single gross figure, you can fail the €70,000 taxable-gross test even though the all-in check looks large.

Package piece	Belgian income tax (2025+)	Belgian social security (still 2022 frame)	US Form 1040 starting point
Qualifying gross (must exceed €70,000)	Taxable in Belgium	In the ONSS base	Worldwide wages; FEIE/FTC may apply
Costs proper to the employer up to 30% of gross	Tax-free	Generally outside ONSS, subject to the old €90,000 cap	Still income unless excluded or credited
Extra 5% to reach 35%	Tax-free from 1 January 2025; no €90,000 cap	Still in the ONSS base until social-security rules change	Same as other wages for US purposes
Documented move, first-six-month furnishing up to €1,500, Belgian school fees	Tax-free if real and receipted, on top of the 35%	Confirm with payroll; not automatic	Often still US income; keep invoices

BDO’s January 2026 note used a clean mismatch example: €90,000 gross plus 35% allowances. Income tax can ignore the full €31,500. Social security still ignores only 30% (€27,000) and taxes the leftover €4,500. The employer’s ONSS bill and your net cash will not match a naive 35% spreadsheet.

Beginners should not self-amend 2025 Belgian filings. If you were already on the regime, the circular lets the employer amend the 2025 salary form 281.10 and the monthly withholding returns after a contract addendum. If you were in the €70,000–€75,000 band and missed the 9 April 2026 special window, do not assume a 2026 application can reach back. Ordinary late filings still fail.

Social Security, ONSS, and the US-Belgium totalization agreement

Belgian employee social security is a different stack from income tax. The inbound regime’s tax-free costs do not automatically pull you out of ONSS, and they do not automatically keep you in US Social Security. Coverage follows the US-Belgium totalization agreement and the certificate of coverage your employer requests, not the 35% election.

If you are hired locally onto a Belgian contract with no US secondment, you normally enter Belgian coverage: old-age, survivors, disability, sickness, unemployment, family allowances, and the rest of the Belgian social code that the agreement lists. SSA’s pamphlet is blunt: workers exempted from Belgian coverage by the agreement pay no Belgian social-security taxes for those programs and generally cannot collect those Belgian benefits, so you need a replacement plan if the certificate keeps you on US FICA instead.

US employers who second you into Belgium request the Belgian certificate from the National Social Security Office (ONSS/RSZ) at Victor Hortaplein 11, B-1060 Brussels, and keep it for an IRS audit. Self-employed people, if they are even in Belgium at all, request coverage certificates from INASTI and attach a copy to the US return each year. For how certificates interact with self-employment tax more generally, use the US totalization agreements guide rather than assuming the inbound income-tax ruling answers the FICA question.

Starter path versus operator path

Starter path: if the offer is a Belgian local contract, budget full Belgian employee contributions on the ONSS base, including the extra 5% that income tax now ignores. Do not promise a US Social Security credit year unless a certificate says so.

Operator path: if you remain on a US payroll with a posted-worker certificate, confirm the certificate’s end date before year two. Belgian income-tax inbound status can run five plus three years. A totalization posting is often much shorter. When the certificate expires, ONSS can attach even if FPS Finance is still honoring the 35%.

FBAR and Form 8938 on Belgian accounts

A Belgian current account, term deposit, group-insurance policy, or employer-sponsored investment account is a foreign financial account. File FinCEN Form 114 if the aggregate value of all foreign accounts exceeds $10,000 at any time during the calendar year — the threshold on the FinCEN FBAR page. The inbound regime does not raise that bar.

Specified foreign financial assets also hit IRS Form 8938 at higher, living-abroad thresholds. Per the current Form 8938 instructions, an unmarried specified individual living abroad files if assets exceed $200,000 on the last day of the year or $300,000 at any time. Married filing jointly abroad files at $400,000 / $600,000. A Belgian salary account plus a taxable brokerage in Dublin or Luxembourg can clear those numbers in one bonus month.

Value foreign accounts with the year-end exchange rate even if you closed the account earlier in the year. Keep the 28 August 2026 Fed print ($1.1598 per euro) out of the FBAR file; FBAR and Form 8938 want the Treasury or year-end rate the instructions specify, not a summer H.10 snapshot you used to size an offer.

1. Split the offer into taxable gross, 30% ONSS-exempt costs, extra 5% tax-only costs, and receipted move/school items.
2. Confirm the 60-month / 150-kilometer / no Belgian professional-income tests with address history, not with a passport stamp collage.
3. Calendar the employer’s three-month FPS Finance filing from the Belgian start date, and the five-year extension filing three months after year five.
4. Ask ONSS/payroll in writing whether the extra 5% sits in the social-security base.
5. Model US Form 2555 at the 2026 $132,900 cap against Form 1116 using Belgian tax actually paid.
6. If you are seconded, get the totalization certificate before the first Belgian payslip.
7. Inventory Belgian accounts for the $10,000 FBAR test and the Form 8938 living-abroad tests.
8. Keep move, furniture, and school invoices; those extras are receipt-based, not automatic.

Families, researchers, and people who should walk

Families can stack documented Belgian school fees on top of the 35% recurring allowance. That is real cash-flow if Brussels or Antwerp international-school invoices would otherwise come from after-tax pay. It is not a dependent exemption, and it does not create a US education credit. The 150-kilometer lookback applies to the inbound employee, not to a trailing spouse’s remote US job — but a spouse who takes a Belgian local contract is in ordinary Belgian tax, not in your ruling.

Researchers should prefer the inbound-researcher track when the €70,000 floor is the problem. The researcher path still needs the 60-month geography tests, the three-month filing, and the five-plus-three duration. It does not need the salary floor. It does need 80% qualifying research time and the degree or ten-year experience test. A product manager with a science master’s who spends 40% of the week in standups will not pass.

Walk away if you are a pure remote contractor billing a Belgian client from Lisbon, if you already lived in Lille or Maastricht, if the employer will not file in month one, or if the “€70,000” is a cost-to-company blob that collapses below the floor after the 35% is pulled out. Walk away from any pitch that says Belgian territoriality or the inbound ruling lets a US citizen skip Form 1040.

Build the Belgian package, then the US file

Belgium’s 2025 rewrite is a cash-flow lever for people who were already going to take a Brussels, Antwerp, or Ghent employment contract. The €70,000 floor, the 35% costs cap, and the death of the €90,000 lid can move five figures of Belgian income tax. They do not move US citizenship-based taxation, they do not yet move ONSS in lockstep, and they expire after five years unless the extension is filed on time.

Get the split written into the contract. Get the FPS Finance filing on the employer’s calendar. Then build the US return around tax actually paid in Belgium, not around the marketing percentage on the mobility slide.

Data notes / Sources checked

• IRS tax year 2026 inflation adjustments (FEIE $132,900)
• IRS Revenue Procedure 2025-32
• IRS Form 1116, Foreign Tax Credit
• IRS Instructions for Form 8938
• FinCEN FBAR (Form 114) $10,000 aggregate test
• SSA totalization agreement pamphlet — Belgium
• Federal Reserve H.10 foreign exchange rates (euro, 28 August 2026)
• EY Belgium summary of Law of 18 December 2025 and circular 2026/C/51
• Deloitte Belgium alert on circular 2026/C/51
• KPMG Belgium 2026 inbound-regime leaflet (eligibility, 35%, €1,500 furnishing, procedure)