Registro Mercantil
Companies Register · Mercantile Register
Spain's public register of companies, their officers and their annual accounts.
Companies register their incorporation, registered office, directors and changes, and file their annual accounts each year. Anyone can request this information, including online through the registrars' portal.
Before reserving an Off-plan home, checking the developer's entry and accounts shows who you are dealing with and how solid the company is. See how to check a developer.
Source: Registradores de España