The Tax Agency warns

The Tax Agency has developed two apps for IOS and Android mobile devices: Agencia Tributaria and Cl@ve PIN. These applications are available to download for free from the official Apple App Store and the Google Play Store, and do not contain any advertisements. You can find these apps in the official app stores by searching for the seller or developer, which is either Agencia Tributaria or Agencia Estatal de Administración Tributaria. Do not trust any other application offering tax-related services, for example, Personal Income Tax Campaign.