A formal perspective on double taxation for companies and individuals with cross-border income
Spain’s Non-Resident Income Tax (IRNR) is the domestic framework that governs how non-residents are taxed on Spanish-source income. In practice, however, double tax treaties (DTTs) and EU directives can limit Spain’s taxing rights or reduce withholding at source, provided that the legal requirements are met. Where Spain has withheld more than corresponds under a treaty or EU rule, the Spanish Tax Agency offers a refund mechanism for non-residents.
The strategic question is not merely “what the law says”, but how to apply it so that the correct jurisdiction taxes the income—and only once. For many taxpayers, the immediate pain point is withholding at source: Spain may apply a default rate, yet the applicable treaty or EU directive would allow a reduced rate—or no Spanish tax at all in certain cases. In such scenarios, Spain should refund the excess, subject to proper documentation.

Companies: common cross-border income patterns and what to check

Business profits and permanent establishment (PE). Under the OECD Model and typical DTTs, business profits are generally taxable only in the state of residence unless the enterprise has a permanent establishment (PE) in Spain. If there is no PE, Spain should not tax those profits; if withholding was nevertheless applied, relief is available through the non-resident refund procedures.
Dividends, interest and royalties. Domestic non-resident withholding in Spain is 19% for dividends and for interest, unless a DTT or (within the EU) a directive reduces the rate or brings it down to 0%. In group contexts, the Parent-Subsidiary Directive and the Interest & Royalties Directive can eliminate withholding when stringent conditions are satisfied (e.g., participation thresholds, subject-to-tax tests, associated-company requirements, beneficial ownership).
Relief at source vs. refund. Two operational routes exist: (i) apply the reduced rate at source by providing the payer with the correct documents; or (ii) pay the default rate and seek a refund from AEAT. The wrong choice—or incomplete paperwork—translates into cash locked for months.

Individuals: frequent issues and corrective avenues to avoid double taxation

For individuals (e.g., private investors or professionals without a Spanish PE), Spain may withhold at 19% on dividends or interest by default. If the treaty cap is lower or the income is not taxable in Spain (under the relevant treaty article), the excess should be refundable via the non-resident procedures (commonly, Model 210, with supporting evidence of residence and beneficial ownership).

How Spanish domestic law and treaties to avoid double taxation interact

The IRNR (Royal Legislative Decree 5/2004) defines the domestic taxing rights on Spanish-source income for non-residents. Where a DTT applies, it prevails in practice by allocating or limiting taxing rights between Spain and the residence state (e.g., Articles 7, 10, 11, 12 of the OECD Model on business profits, dividends, interest and royalties). In the EU, the Parent-Subsidiary and Interest & Royalties directives may provide exemptions at source when conditions are met. (BOE)

Documentation: where most problems actually arise

In our experience, disputes and delays stem less from the rulebook and more from documentation gaps. As a minimum, consider:

• Tax residence certificate valid for the relevant period.
• Proof of withholding from the Spanish payer.
• Contracts/invoices that support the income category under the treaty (dividend, interest, royalty, business profits) and the beneficial owner.
• No-PE support for business profits (substance, functions, decision-making outside Spain).
• Transfer pricing support for intra-group payments where applicable.

Without this, payers tend to apply the default rate, and the Tax Agency may delay or deny refunds.

When the Spanish Tax Agency must refund

If Spain has withheld above the treaty rate or taxed income that is not taxable in Spain under the applicable treaty (for example, business profits without a PE), non-residents can request a refund through the IRNR channel. The Model 210 instructions detail the procedure and deadlines; timely submission and complete evidence are essential.

EU directives as double taxation relief drivers

Within the EU, the Parent-Subsidiary Directive can reduce withholding on qualifying dividends to 0% and the Interest & Royalties Directive can do the same for qualifying payments between associated companies—subject to strict eligibility and anti-abuse rules. Diligent verification of participation thresholds, legal forms, subject-to-tax and holding-period conditions is indispensable.

A note on scope and governance

Domestic Spanish rules set the starting point, but relief turns on treaty/EU eligibility and evidence. Approaching this as a compliance formality often leaves money on the table. A governance-minded approach—up-front eligibility analysis, documentation packs for payers, and coordinated filings—minimises leakage and disputes.
Our practical experience. LegalTaxSpain routinely addresses cases where domestic withholding was applied despite available treaty or EU relief. The added value lies in diagnosing eligibility, assembling the legal and accounting evidence, and handling refunds when Spain withheld more than it should—without turning the process into an administrative loop. (The refund framework and Model 210 route are set out by AEAT.)
Maintaining the structure once the refund is obtained. Relief is not a one-off event. Keep residence certificates current, monitor PE risk, align contracts and invoices with the right treaty article, and calendar renewals so relief applies at source rather than by refund. If you need ongoing help to keep a compliant structure, see our services for non-resident taxation in Spain.