Volunteering is great. But it’s not the same as working. Volunteers help out on their own terms. They can come and go as they please, not worry about performance measures or their boss checking up on them. They don’t have a list of responsibilities, they only have tasks that they agree to take on. Volunteers don’t do a task for money or CV points, they do it for the love of it or to help a good cause. Most internships are very different to this. The vast majority of interns have a list of duties and times between which they work. That’s not volunteering, that’s working and therefore the intern has a legal right to be paid.