For the last couple of years, the Agencia Tributaria has been rolling out a service by which Spanish companies and Spanish establishments of overseas companies are required to register for Electronic Notifications (NotificacionesElectrónicas Obligatorias).
Annual income tax: for non-residents with no rental income
If you own a Spanish property which you do not rent out, then you are still obliged under Spanish tax law to submit an annual tax return and pay the tax due.
Over the twelve years that I have been practising in Spain, I have taken on work from several non-resident clients who wish to reclaim the overpaid tax on the sale of their Spanish properties. Over that time, the tax rates and returns have changed, while one thing has stayed the same: it’s an awfully slow process !