RSUs in Spain. In Spain an RSU is not a legal category: it is a contractual promise to which rules written for something else are applied. The characterisation comes out of your plan document, not out of the name of the instrument, and that is where two colleagues with the same grant end up with two different returns.
Rachel Kim is a US citizen, born in Oregon, who has lived in Seville since 2023 with her Spanish partner. She works remotely for a Denver software company, which in 2026 will vest RSUs worth 60,000 € for her. During the year she will travel to the United States for work for about twenty days. She knows Spain considers her resident and requires her to declare her worldwide income. She also knows her own country still expects an annual return from her. Her question is the one almost every American with equity in Spain asks: will I pay the tax on the RSUs twice? The answer depends on where each part of the income is treated as obtained and on which country corrects the double taxation in each case.
What Spain asks of a resident
As a tax resident in Spain, Rachel is liable to Spanish income tax (IRPF) on all her income, whatever the country in which it is obtained or the payer. Her RSUs will be taxed in Spain as employment income in kind in the year they are delivered to her, at their value on that day. None of this changes because of her nationality: Spanish income tax is charged by residence, not by passport. The detail of the calculation is in how RSUs are taxed.
The saving clause: what the treaty does not prevent
The double taxation treaty between Spain and the United States, like all such treaties, divides the power to tax between the country of residence and the country of source. But it includes a saving clause under which the United States reserves the right to tax its citizens as if the treaty did not exist, except in the cases the clause itself excludes. In practice, that means Rachel cannot rely on the treaty against the United States as a Spanish resident without a US passport would.
How Rachel is taxed in the United States, which exclusions or credits she can apply there and on which forms, is not something we explain: her US adviser confirms it, and we coordinate with them. Nor do we promise a network of advisers there; Rachel appoints her own.
Which part of the income is Spanish and which is not
From the Spanish side, the useful question is a different one: what part of Rachel's income has been obtained abroad? Only that part can give rise to the international double taxation deduction in article 80 of the Spanish Income Tax Act, which applies when the taxpayer's income includes income "obtained and taxed abroad".
For employment income, the general criterion in treaties looks to the place where the work is physically performed. Rachel works from Seville almost all year: that income is obtained in Spain. The twenty days she works in the United States, on the other hand, may be regarded as work carried out there.
| Part of the income | Where it is obtained | Who corrects the double taxation |
|---|---|---|
| Work physically performed in Spain | Spain | Under the treaty and its own rules, the United States, as the country of citizenship |
| Work physically performed in the United States | United States | Spain, under article 80, within its limits |
| Dividends from the Denver company | United States, with withholding at source under the treaty | Spain, under article 80 |
The Spanish deduction, step by step
Suppose Rachel works 220 days in 2026, of which she spends 20 in the United States, and that the RSUs relate to work in that same year. The amounts are for the example:
- Value of the RSUs: 60,000 €.
- Part attributable to work in the United States: 60,000 × 20 / 220 = 5,454.55 €.
- Tax actually paid in the United States on that part, according to her return there: suppose 1,200 €.
- Rachel's effective average rate in Spain, which comes out of her own return: suppose 31.40 %.
- Limit at the average rate: 5,454.55 × 31.40 % = 1,712.73 €.
- Deduction: the lower of the two amounts, 1,200 €.
Article 80 limits the deduction to the lower of two figures: what was paid abroad in a similar tax, and the result of applying the Spanish effective average rate to the part of the base taxed abroad. The guide on the international double taxation deduction develops the calculation. If the United States also taxes the part worked in Seville, that double taxation is not corrected by article 80, because the income was obtained in Spain.
The Spanish deduction needs to know what was actually paid in the United States, and the US relief needs to know what was paid in Spain. The filing seasons do not coincide and neither do the exchange rates. If one of the two returns is filed with provisional figures, it may need correcting later. We cannot guarantee that both administrations will accept the same split of days.
You can send us your travel calendar, the vesting documents and the year's US return through the equity form so that the Spanish side can be squared with what Rachel's adviser prepares there.
And when she sells the shares
If Rachel sells the shares she received in 2027, the gain is calculated in Spain as the difference between the sale price and the value at which they were taxed as employment income, each converted at the rate of its own date. Suppose the shares were worth 60,000 € when she received them and she sells them for 66,500 €: the Spanish capital gain is 6,500 €, in the savings base. As a resident, Spain taxes that gain even though the company is American and the broker is in New York. If the United States also taxes it because of Rachel's citizenship, the way to avoid paying twice is examined in the US return, with her adviser there, because from the Spanish point of view it is not income obtained abroad that gives a right to article 80.
Records worth keeping
The evidence for the split is the real work calendar: tickets, records of entries and exits, meeting diaries. Without it, the part attributed to the United States is just an assertion. You also need evidence of the tax actually paid there, because article 80 refers to the "actual" amount, not a theoretical one. If the United States also regards you as resident for some reason, before any of this the residence conflict has to be resolved under the treaty's rules, which we cover in the guide on dual residence conflicts.
Other pieces that affect an American with equity
The article 93 regime. An American who moves to Spain to work can opt for the special regime if they meet the requirements. Under it, RSUs are taxed at the regime's rate and the sale of shares in the US company falls, in principle, outside. We explain it in the Beckham regime and shares.
Modelo 720. Shares held with a US broker count towards the securities block of this Spanish return on assets held abroad if they exceed the thresholds. It is covered in options and Modelo 720.
Plans with American names. A discounted share purchase plan or ISOs have their own treatment in the United States that Spain does not recognise. We cover this in ISO or NSO and in ESPP.
Coordinating the Spanish and US returns is one of the situations we describe on the Salama Tax page on equity, always with the client's US adviser on the other side.