UNTUCKit UK is a brand that specializes in designing casual men's shirts to be worn untucked. They offer a variety of styles, including regular and slim-fit button-downs, sweaters, tees, henleys, and polos. The brand has recently expanded to include women's button-down shirts as well. UNTUCKit UK caters to the modern, casual lifestyle, providing a comfortable and stylish solution for men and women who prefer a more relaxed, untucked look.