What level of Spanish do I need to work in Spain

If you are thinking of coming to Spain, Id suggest you take at least one Spanish course before hand, just so you can defend yourself in any circumstance. You don't want to show up to another country without knowing any of the language, some basic spanish skills would be very helpful for you, specially if you are coming on an internship. I would recommend any Spanish online courses, or sign up for a course in your college. Find out what facilities there are in your destination - for example in Alicante there is a Escuela Oficial de Idiomas where they teach Spanish or any other language that you wish to learn.

Also, spanish people appreciate when you make the intent to speak, so dont feel embarrassed of your accent, adapt to the culture and get yourself involved! thats the great part! The more you practise your spanish, the better you will get at it! Remember its a process of learning.

However, as for needing spanish at work, this is a yes, just so there arent any misunderstandings. Communicating is key when your at work, sometimes you may not understand certain things or your colleague wont understand you. Its obvious that it is not expected of you to dominate the language like a native speaker, but as long as you can explain your self pretty well, than you are set and ready to go.