The so called "Beckham Tax" was introduced into Spanish tax law in order to attract the footballer David Beckham to play for Real Madrid years ago. But it couldn't be introduced for just him, so many others have benefited. In order to qualify you had to (amongst other things) have not worked in Spain before, be employed by a Spanish company, apply within 6 months of starting work in Spain etc. The tax rate used to be 24% flat rate with no other tax allowances (for kids, mortgage relief etc.). The tax rate is now 24.75% as far as I know. It lasts for 5 years, after which it's normal taxation from then on, unless you've left employment with a Spanish company before then of course.