For British nationals engaging in courses or traineeships that last no more than 90 days in Spain, a visa is not required. If a British citizen requires a Schengen visa for other reasons, they must apply for a Schengen Tourism Visa.
For internships linked to recent university degrees or ongoing studies aimed at degree attainment, a specific visa is required to enhance professional skills through an internship agreement or trainee contract. If these conditions are not met, other types of internships may necessitate applying for a study visa, which accommodates a broader range of internship activities.
Learn more about it in our Spanish VISA article and here’s the form