What is the AEAT and what does it have to do with the Modelo 210?

AEAT stands for Agencia Estatal de Administración Tributaria — Spain's national tax authority. It is the equivalent of HMRC in the United Kingdom or the IRS in the United States, but operates at the national level for the entire country, excluding the Foral territories. The AEAT is responsible for administering, collecting and enforcing state-level taxes in Spain, including the IRPF for residents and the IRNR for non-residents. The Modelo 210 is filed with and processed by the AEAT. For non-residents, the AEAT's role is threefold. It receives the Modelo 210 declaration and processes the associated payment. It reviews filings for accuracy and can initiate audit procedures where discrepancies arise. And it issues the Justificante — the official filing receipt that serves as proof of tax compliance, which some owners need for their home-country tax returns or when selling the property. The AEAT operates an electronic platform, the Sede Electrónica, through which tax returns can be filed online. For non-residents without a Spanish digital certificate or Cl@ve PIN, the process is cumbersome — the interface is primarily in Spanish, the authentication requirements are stringent, and the form itself requires familiarity with Spanish tax codes and categories. This is why many non-resident owners use a Gestor, an Asesor Fiscal, or a specialised platform such as Fiscaro to handle the filing. One important reference point: the AEAT publishes the Manual Renta annually, which documents the current interpretation and application of tax law. For the calculation of the imputation rate (1.1% or 2.0%), the Manual Renta 2025 §7.3.4 is the authoritative reference, read together with the Disposición Adicional 55 LIRPF. Any platform or adviser that calculates imputed income should be working from this basis. The AEAT also administers the Modelo 211 process — the 3% retention withheld by buyers when purchasing property from non-residents — and handles the subsequent refund claims filed through the Modelo 210.