When do young witches and wizards lose there trace?

Young witches and wizards lose their trace when they reach the age of 17, which is considered the age of maturity in the wizarding world. At this point, they are allowed to perform magic without the restrictions imposed on minors. The trace is a magical signal that allows the Ministry of Magic to detect underage magic use, and its removal signifies a young wizard or witch's transition into adulthood.