Foreign brokers from Spain: which obligations trigger

Low-cost foreign brokers are perfectly legal to use from Spain (when EU-authorised or passported: check with our CNMV guide). What changes is not the tax: it is who does the work. A Spanish broker withholds and reports for you; with a foreign one, the accountant is you. Rules verified as of this guide’s date; general information, not advice.

What does NOT change

The tax bill. Gains and dividends are taxed the same in your savings base (19-30% since 2025, the 30% top rate applying above 300,000 euros under Ley 7/2024) whether the securities sit in Madrid or Frankfurt. The myth that “the tax agency cannot see foreign brokers” died years ago: Europe’s automatic exchange of account data (CRS/DAC2, form 289) reports accounts and balances between administrations routinely, and DAC8 extends that exchange to crypto platforms.

What does change: the work is yours

A Spanish broker withholds tax and feeds your pre-filled return. A foreign one withholds no Spanish income tax and feeds nothing: every sale, dividend and gain gets reconstructed by you from its annual reports, and the pre-filled draft arrives empty on that side. The practical consequence: export the broker’s annual tax report every January and keep it; rebuilding years of history after the fact is the classic expensive accountant job.

Foreign dividends and the double withholding

A dividend from a US or German share is withheld AT SOURCE (15% under the US treaty if you filed the W-8BEN, more elsewhere) and is then taxed in your Spanish return as well. The double-taxation treaty lets you credit the source withholding in Spain up to the treaty rate; anything withheld ABOVE the treaty rate (typical in Germany or France without the reduction paperwork) is only recovered by claiming from the source country’s tax agency. It is international dividends’ most expensive fine print.

The nuance that changes everything: the Spanish branch

The 720/721 criterion is WHERE the entity sits, not its brand. When a broker opens a Spanish branch and migrates you to a Spanish IBAN, your positions stop being “abroad”: exactly what happened with Trade Republic (ES IBANs since June 2025, with the tax directorate confirming the 720 and 721 exemption) and with Revolut’s account. Before assuming the full foreign manual, check the letter pair of your IBAN and the entity’s domicile in your contract: half the guide may no longer apply to you.

The 720 yes, the D-6 no more

With over 50,000 euros of securities held abroad on 31 December, form 720 is filed (informative, January to March, same repetition rules as crypto’s 721). The old D-6 filing with the trade ministry, which duplicated part of that information, was abolished by Orden ECM/57/2024, of 29 January 2024: a guide still asking for it is out of date. The fine thresholds and edge cases are advisor territory; the map above is the part you cannot skip. Checked 2026-08-22 against the AEAT form 720 page.