I currently live in Spain but work in Gibraltar. I commute daily as many others do. I have a property in Spain registered in mine and my wife’s name at a value of €300,000. I pay income tax in Gibraltar as it is deducted at source but am aware I don't currently declare anything in Spain although I live here. I have heard that I should be registering some kind of annual return as I own a property and I am here more than 183 days a year. I am concerned if I start registering in Spain that another tax bill is going to appear. Would this be the case? I am also not sure if I should be applying for full residency in Spain and how this affects the above. Any help would be much appreciated. Thanks