According to the U.S. Department of Labor's Fair Labor Standards, a 12-year-old is not allowed to work in a shop. The minimum age for working in a shop is 14 years old; however, the hours a 14-year-old may work are severely restricted.
Although 14 is the minimum age for non-agricultural work in the United States, 12-year-olds are permitted to work in agriculture. They are only permitted to work when school is not in session and may not perform hazardous jobs. Children 12 years old may only work if a parent works on the same farm or has given written permission for the child to work. Children under 12 may only work in agricultural jobs on farms that are so small that they are not required to pay the minimum wage.