Schengen just means you don't have to present your passport at the border. However that differnet from "not requiring a visa". Both UK & Ireland allow any EU ci

Schengen just means you don't have to present your passport at the border. However that differnet from "not requiring a visa". Both UK & Ireland allow any EU citizen to work in their countries without a visa. So you only need to show a passport to enter UK/Ireland, but that's all. You still have free movement of people between (say) UK and Bulgaria.