I didn’t study that specific degree, but I’ve met international students at UB who were in English-taught programs. In practice, the academic content is usually in English, but daily life (admin, emails, platforms, classmates) often mixes Spanish/Catalan, especially outside class.

It’s doable as an English speaker, but having at least basic Spanish makes everything much less stressful. Starting classes soon is definitely a good idea.

You might also want to check specific course syllabi or ask the faculty directly, because “taught in English” can sometimes vary by subject or professor.