IRNR
Non-resident income tax · Impuesto sobre la Renta de No Residentes
Spain's income tax on non-residents, including on rental income and on property they own but do not rent out.
On rental income the rate is 19% for residents of the EU and EEA (with tax information exchange) and 24% for others, including the UK and the US (art. 25.1.a TRLIRNR). A home that is not rented out is taxed on an imputed income. It is declared with Modelo 210.
Source: Agencia Tributaria: IRNR rates