I am a U.S. citizen and an independent contractor who provides (public relations) services to U.S. companies. I want to move to Spain to live for one year, while continuing to provide my clients services and working remotely from Spain. I need to know a) what visa type to apply for before going there and b) what forms to file in Spain to ensure I am paying Spanish taxes so I am there legally.

You are a Non-EU citizen so be prepared for an answer like: “No, this is not possible AT ALL because why would they give you a work permit.”

Don’t forget you are talking about going to a country with 26% unemployment.

There is a Work Visa program but it is basically meant for employees from overseas. Since you are self-employed, I don’t think you can get this visa.

Matthijs’ answer is not correct.

You are not coming to spain to look for work. you are already employed. you will need to declare and prove this when applying for your visa. your visa application should not be for work, because it isnt, but for living in spain. ALSO you should apply for a work permit to be able to continue doing your job.

you will have to pay taxes in spain per law. you will probably register as autonomo, meaning self employed.