Belgium taxes options at grant on a lump sum, Luxembourg at exercise, the Netherlands when the shares become tradable. Treaties do not align these clocks; they split the gain. Under the OECD Commentary on Article 15 an option rewards the work between grant and vesting, so each country taxes the share earned by working days there, and the residence state exempts the rest with progression, whenever the other state taxed. Relief is claimed, not automatic, and the new Belgium-Netherlands treaty is not yet in force. Shares already held can trigger the Dutch box 2 conservatory assessment or the new Belgian exit charge.
An option earned in two countries is taxed in two countries
An executive who moves between Amsterdam, Luxembourg and Brussels with unvested equity carries three tax clocks. The Netherlands taxes options when the shares become tradable, Belgium at grant on a lump sum, Luxembourg at exercise. Restricted stock units (RSUs) are taxed at vesting nearly everywhere.
Treaties do not change the clocks. They decide which country may tax which part. The OECD Commentary on Article 15 treats an option as pay for the work done between grant and vesting, and splits the gain by working days spent in each country during that period. The country where you live when the tax falls due then exempts or credits the part earned abroad.
The trouble sits between the two layers. A Belgian grant taxed in year one and a Dutch exercise taxed in year five fall in different years, under different formulas, and relief has to be claimed.
For the domestic rules see our notes on Belgian stock options, the Luxembourg management incentive plan and Dutch employee stock options.
Tradability
Wage at up to 49.5%, or at exercise by election.
Grant
Lump sum on the 60th day after the offer.
Exercise
Benefit in kind at up to 45.78%.
Grant to vesting
Working days in each country, OECD method.
When each country taxes options and RSUs
Netherlands. An option is wage. Since 2023 it is taxed when the shares acquired on exercise become tradable, unless the employee elects exercise. The benefit is taxed in box 1 at up to 49.5% (above EUR 78,426 in 2026), withheld by the employer. RSUs are wage at vesting.
Belgium. Under the Law of 26 March 1999 an option accepted in writing within 60 days is taxed on the 60th day after the offer, on a lump sum: 18% of the underlying share value plus 1% per year of term beyond five, halved if the plan meets the statutory conditions. Exercise is outside income tax; later growth falls under the 10% capital gains tax from 2026, with the value at exercise as acquisition value. An option accepted late is taxed at exercise. RSUs are taxed at vesting. Top rate: 50% plus municipal surcharge.
Luxembourg. Since the options circular was withdrawn from 2021, a non-transferable option is taxed at exercise as a benefit in kind, RSUs at vesting, at up to 45.78%. Bill 8782 of 1 July 2026 would add a start-up regime taxed at sale; it is not law.
| Country | Options taxed | RSUs taxed | Allocation for mobile staff |
|---|---|---|---|
| Netherlands | Tradability, or exercise by election | Vesting | Time-proportional, OECD para 12 (decree of 22 November 2024) |
| Belgium | Grant (60th day), lump sum | Vesting | Presumed to relate to work at grant; rebuttable |
| Luxembourg | Exercise | Vesting | Luxembourg working days for non-residents |
| United Kingdom | Exercise | Vesting | Workdays from grant to vesting (ITEPA 2003, Part 2, Chapter 5B) |
| United States | Exercise (non-qualified options) | Vesting | Days from grant to vesting (Treas. Reg. 1.861-4(b)(2)(ii)(F)) |
| Germany | Exercise | Vesting | Grant to first exercisability (BFH case law) |
| France | Sale for qualified plans, exercise otherwise | Vesting or sale, by plan | Days from grant to vesting (BOFiP BOI-RSA-ES-20-10-20-60) |
| Spain | Exercise | Vesting | Proportional to Spanish work (DGT V0813-23) |
Outside the Benelux the table is a pointer only: plan-specific regimes apply, and the UK-US treaty uses grant to exercise.
Law and practice: Wet op de loonbelasting 1964, Article 10a (Stb. 2022, 539); Law of 26 March 1999, Articles 41 to 49; capital gains tax on financial assets adopted 3 April 2026 (Claeys & Engels analysis, May 2026); L.I.R. Articles 95 and 104; bill 8782 (Deloitte Luxembourg); HMRC ERSM163120; US Treas. Reg. §1.861-4; BFH I R 11/20 of 21 December 2022 (EY Germany); BOFiP BOI-RSA-ES-20-10-20-60; DGT V0813-23 of 5 April 2023 (Cuatrecasas).
Article 15 Commentary: the gain follows the working days of the vesting period
Paragraph 12.2 of the Commentary on Article 15 draws the line: the benefit up to exercise or sale of the option is employment income; growth on the shares afterwards is a capital gain under Article 13. Paragraph 12.3 leaves the timing to the source state, which may tax at grant, vesting, exercise or sale, but only the employment part.
Paragraph 12.7 states the principle: an option does not relate to services after the period required to acquire the right to exercise it, the vesting period. A mere blocking period does not count (12.8), nor does a clause forfeiting a vested option on leaving (12.9).
A sign-on grant or a grant on transfer may reward other periods (12.10); past services count only where the grant clearly rewards them (12.11); accelerated vesting on dismissal limits the period to work actually done (12.12). Paragraph 12.14 gives the formula: split by the days worked in each state in the relevant period. Paragraph 12.15 allows other bilateral methods.
| Step | Question | Typical answer |
|---|---|---|
| 1 | What period does the award reward? | Grant to vesting; past results only if the grant says so |
| 2 | Where were the working days in that period? | Diary, payroll and travel records, not the contract |
| 3 | Which state is the source of each share? | The state where those days were worked |
| 4 | Which state is the residence state at the taxable moment? | Where you live when the residence state taxes |
| 5 | How does it relieve the foreign share? | Exemption or credit under the treaty, regardless of timing |
Timing and relief. Under paragraph 32.8 of the Commentary on Articles 23 A and 23 B the residence state must give relief regardless of when the source state taxes. Paragraphs 4.1 to 4.3 take the case of one state taxing at grant and another at exercise after a move: the state where the work was done is the source and the other relieves.
The Netherlands follows the Commentary expressly: its decree of 22 November 2024 splits the taxing right time-proportionately and treats growth between exercise and tradability as shareholder income. Belgium presumes an option rewards the work at grant, a rebuttable view. Most administrations apply the same reasoning to RSUs.
Law and practice: OECD Model Tax Convention, Commentary on Article 15, paragraphs 12 to 12.15; Commentary on Articles 23 A and 23 B, paragraphs 4.1 to 4.3 and 32.8. Besluit fiscale behandeling van aandelenoptierechten in grensoverschrijdende situaties, 22 November 2024, nr. 2024-20586, Stcrt. 2024, 38523, sections 4 to 9. Grant Thornton Belgium, share options in cross-border employment between Belgium and the Netherlands.
Netherlands, Belgium, Luxembourg: which treaty, which relief
All three treaties follow the OECD employment article, so each state may tax its working-day share. Relief is by exemption with progression: the residence state leaves out the foreign share but uses it to set the rate.
| Pair | Treaty in force | Relief for employment income | Point to watch |
|---|---|---|---|
| Netherlands-Belgium | 2001 treaty; new treaty signed 21 June 2023, not in force | Exemption with progression; Belgium refunds part of the grant tax on request | Belgian grant tax and Dutch exercise tax fall in different years |
| Netherlands-Luxembourg | 1968 convention as amended by the 2009 protocol | Exemption with progression | Dutch tradability can be years after Luxembourg would tax |
| Belgium-Luxembourg | 1970 convention as amended | Exemption with progression | 34-day tolerance for commuters since 2022 |
Netherlands and Belgium. The 2001 treaty still applies. Its successor, signed on 21 June 2023, had not entered into force by November 2026; BDO expects 2027. It takes options out of the frontier-worker compensation scheme where the two states tax in different years, but does not fix the timing mismatch. Belgium refunds the Dutch share of its grant tax only once the Netherlands has taxed it, and only on request; after a late exercise the refund may be lost.
Netherlands and Luxembourg. The 1968 convention, amended by the 2009 protocol in force since 1 July 2010, applies; we found no successor signed. Luxembourg taxes its share at exercise, the Netherlands at tradability; the Dutch exemption is due even if the years differ, but expect to prove it.
Belgium and Luxembourg. The 1970 convention governs, with a 34-day tolerance for commuters since 2022. Belgian residents moving to a Luxembourg company should expect Luxembourg to claim its share of anything that vests later.
An executive of a listed Belgian group accepts 20,000 options within 60 days: exercise price EUR 10, share value at the offer EUR 10, underlying value EUR 200,000, term ten years, cliff vesting after four, halving conditions met. The lump sum is 9% plus 0.5% for each of five years beyond five, 11.5%, or EUR 23,000; at 53.5% Belgium collects EUR 12,305. After 440 working days he moves to the Amsterdam company and works 440 days there until vesting. In year five he exercises at EUR 30: a gain of EUR 400,000, tradable at once. The Dutch payroll withholds 49.5% on all of it, EUR 198,000. Under the OECD split half is Belgian, so the Netherlands exempts it and keeps EUR 99,000, and Belgium refunds half its grant tax, EUR 6,152, on request. After relief: about EUR 105,150. Before relief: EUR 210,305.
Law and practice: Convention between the Netherlands and Belgium of 5 June 2001 (Trb. 2001, 136) and new convention signed 21 June 2023 (AKD, Grant Thornton, BDO Belgium-Holland Country Desk newsletter April 2026); Convention between the Netherlands and Luxembourg of 8 May 1968, protocol of 29 May 2009 (treaty database overheid.nl, no. 012170); Convention between Belgium and Luxembourg of 17 September 1970 and protocols; 34-day rule (PwC Belgium, Tiberghien).
Withholding, the payroll split, RSUs from a US parent and the 30% ruling
The employee bears the tax; the employer bears the withholding, and a former employer can remain liable for the part earned with it.
Netherlands. For a non-resident the decree of 22 November 2024 limits wage tax to the Dutch share, and allows growth between exercise and tradability not linked to Dutch work to go unwithheld. For a resident with a foreign share, withholding on the full benefit and reclaiming through the return is common; a payroll split needs documented days.
Belgium. The employer withholds on the lump sum at grant and reports it on form 281.10, including benefits granted by foreign group companies. Since 2026 a 7.5% special employer contribution can apply to lump-sum benefits above 20% of total pay.
Luxembourg. The employer withholds through payroll at exercise or vesting; for a leaver, agree who reports the Luxembourg share.
RSUs from a US parent. The US company does not withhold for non-US staff; the local employer is the withholding agent. In the Netherlands third-party wage (loon van derden) must be included where the employer knows or should know of it, as with any group plan. US citizens stay taxable in the US and rely on the foreign tax credit. Watch sell-to-cover: shares sold for withholding that no Benelux authority receives.
The Dutch 30% ruling. An option benefit is wage and can sit within the allowance base, capped on salary of EUR 262,000 in 2026. The ruling ends with the Dutch employment: in ECLI:NL:HR:2017:2420 the Hoge Raad refused it for options exercised after the employees left. See the 30% ruling.
Social security. Regulation (EC) 883/2004 makes one state competent and does not split by working days; check the A1 position before the taxable event.
A Luxembourg executive receives 6,000 RSUs vesting after three years. After 440 working days in Luxembourg she moves to the Brussels office and works 220 days there before vesting, when the shares are worth EUR 300,000. Two thirds, EUR 200,000, is Luxembourg-source: at 45.78%, about EUR 91,560. Belgium taxes her as a resident and exempts that share with progression: EUR 100,000 at 53.5%, EUR 53,500. Total about EUR 145,060. If the Belgian payroll runs the full EUR 300,000 as well, the claims before relief reach EUR 252,060. For the Belgian capital gains tax, the vesting value should be the acquisition value.
Law and practice: Besluit van 22 november 2024, nr. 2024-20586, sections 5, 6 and 9; Wet op de loonbelasting 1964 (third-party wage); Hoge Raad 22 September 2017, ECLI:NL:HR:2017:2420; Belgian Income Tax Code 1992 and form 281.10; Law of 17 December 2025 (special contribution); L.I.R. Articles 95, 104 and 136; Regulation (EC) No 883/2004, Article 11; Claeys & Engels, analysis of the new capital gains tax, May 2026.
Exit taxes, conservatory assessments and management equity
After exercise or vesting, growth is a capital gain under Article 13, normally taxed by the residence state only. Exit taxes and management packages treated as pay reopen it.
Netherlands: box 2. A holding of 5% or more is taxed in box 2 at 24.5% up to EUR 68,843 and 31% above in 2026. Emigration is a deemed disposal and triggers a conservatory assessment, deferred automatically within the EU or EEA and on request with security elsewhere. A sale or dividend triggers payment. Since 15 September 2015 the deferral no longer lapses after ten years.
Belgium. The capital gains tax adopted on 3 April 2026 includes an exit charge on latent gains. For a move within the EU or EEA, payment is deferred automatically; per Claeys & Engels, the claim lapses on return within 24 months or without a disposal within 24 months. Stakes of 20% or more have their own scale, 0% up to EUR 1 million, then 1.25% to 10%. Arrivals are taxed only on gains accrued while resident.
Luxembourg. No exit tax for individuals, but under Article 156, no. 8 L.I.R. a resident of at least 15 years who sells a substantial shareholding in a Luxembourg company within five years of leaving stays taxable, where the treaty allows.
Management equity. Sweet equity is the hard case. The Netherlands taxes a lucrative interest in box 1 at up to 49.5%, or in box 2 through a personal holding, which then falls under the emigration rule. Belgium and Luxembourg ask whether the return is disproportionate and linked to employment; if so it is pay, allocated by working days. See lucrative interest and management equity and phantom shares, growth shares and STAK plans.
| Country | Exit charge on shares | Deferral | When it ends |
|---|---|---|---|
| Netherlands | Box 2 conservatory assessment, 5%+ holdings | Automatic in EU/EEA; on request with security elsewhere | Payable on sale or dividend; no lapse after 2015 emigrations |
| Belgium | Exit charge under the 2026 capital gains tax | Automatic in EU/EEA and recovery-assistance states | Lapses after 24 months without disposal, or on return |
| Luxembourg | No exit tax; 15-year residents taxed on substantial holdings sold within five years | Not applicable | Five years after departure |
Law and practice: Wet inkomstenbelasting 2001, Article 2.12 and Chapter 4 (deemed disposal on emigration); Invorderingswet 1990, Article 25; Belastingdienst, 'Conserverende aanslag bij emigratie'; Belgian capital gains tax law adopted 3 April 2026 (Claeys & Engels); L.I.R. Articles 100 and 156, no. 8 (Fiduciaire LPG summary). See also exit tax when selling a business.
A checklist for the six months before the move
Most of the cost comes from missing records and missed claims, not from rates.
- List every award. Grant date, vesting schedule, exercise window, leaver clauses, and whether the plan rewards past results.
- Count the days. Keep a day-by-day record of where you worked between grant and vesting for every open award. A payroll split needs it, and so does any refund claim.
- Decide exercise before or after. Exercising a vested option in Luxembourg before a move fixes the Luxembourg charge; exercising after a move from Belgium to the Netherlands adds Dutch tax on the Dutch part. Run both cases.
- Use the Dutch election. Taxing at exercise instead of tradability can align the Dutch charge with the other country's and end the employment part earlier.
- Brief both payrolls. Agree in writing which employer reports which share, and stop sell-to-cover where it serves no tax authority.
- Plan the Belgian refund. If you leave Belgium with options taxed at grant, diarise the refund claim for the year the new country taxes.
- Check holdings of 5% or 20%. Dutch box 2 and the Belgian 20% scale trigger exit charges; Luxembourg looks at 10% and 15 years of residence.
- Ask for a ruling. Dutch prior consultation, a Belgian advance decision or a Luxembourg advance confirmation, before the move, not after the exercise.
If you are setting up a holding or company around the move, our note on moving to the Benelux with your company covers the corporate side.
Law and practice: Grant Thornton Belgium (ruling suggested in complex cases); Belastingdienst, vooroverleg; Belgian Service des Décisions Anticipées (Law of 24 December 2002, Articles 20 to 28); Luxembourg advance tax confirmations, § 29a of the Abgabenordnung.
Who taxes my options when I move?
The calculator splits the gain by working days, shows each country's claim under its own clock and what remains after relief. The defaults reproduce example (a).
Who taxes my options when I move?
Enter the grant, the vesting period, the move and the gain. You get the split of the gain by working days under the OECD method, what each country would claim under its own timing rule, the double-tax exposure before relief and the relief to claim.
The OECD split follows working days in that period.
BE at grant, LU at exercise, NL at tradability.
Exemption with progression, regardless of timing.
Box 2 and the Belgian exit charge follow you.
Moving with stock options: frequent questions
Which country taxes my stock options if I move during the vesting period?
Usually both, each on its share. Under the OECD Commentary on Article 15 the option rewards the work between grant and vesting, so the gain is split by working days in each country in that period. The country where you live when the tax falls due relieves the share earned abroad.
Does it matter that Belgium taxes at grant and the Netherlands at exercise?
It decides when you pay, not who may tax. Relief is due whenever the source state levies its tax (Commentary on Article 23, paragraph 32.8). In practice Belgium refunds the part of its grant tax that relates to Dutch work only if you ask and show that the Netherlands taxed it.
Does the Dutch 30% ruling cover my option gain?
Only while the ruling runs, and within the salary cap of EUR 262,000 in 2026. The Hoge Raad held in 2017 (ECLI:NL:HR:2017:2420) that it does not cover an option benefit enjoyed after the Dutch employment ended.
Will the Netherlands tax my company shares when I emigrate?
If you hold 5% or more, yes: emigration is a deemed sale and the Belastingdienst issues a conservatory assessment in box 2. Within the EU or EEA payment is deferred automatically, but for emigrations after 15 September 2015 it no longer lapses; a sale or dividend triggers payment.
Who withholds tax on RSUs granted by a US parent?
The local employer, as a rule. The US parent does not withhold for non-US employees, so the Dutch, Belgian or Luxembourg payroll must pick up the benefit at vesting.