How many times can car paint safely be polished?

There is no universal number. Safe polishing depends on original paint thickness, previous correction work, scratch depth, pad and compound choice, and how much material is removed each time. A light finishing polish removes far less than a heavy compounding session. Paint thickness measurement and conservative correction are more useful than counting polishing sessions. Careful washing that prevents new swirls is the best way to reduce how often paint needs polishing in the first place.