Weasleys' Wizard Wheezes

"WHY ARE YOU WORRYING ABOUT YOU-KNOW-WHO?
YOU SHOULD BE WORRYING ABOUT U-NO-POO—
THE CONSTIPATION SENSATION THAT'S GRIPPING THE NATION!"

Argus Filch banned all of Fred and George's products from Hogwarts in 1996. However, as no one paid much attention to things Filch banned, this had little effect. They opened a branch in Diagon Alley shortly after leaving Hogwarts in April 1996, employing a shop assistant named Verity. They also intended to buy Zonko's Joke Shop in Hogsmeadein order to extend their business. However, due to Hogwarts security being raised to the point that all Hogsmeade trips were cancelled, they saw no point to this.

George continued to operate the business after Fred's death, despite never fully getting over the loss of his twin.He was eventually joined by his brother Ron, who had previously worked as an Auror alongside Harry Potter to track down Death Eaters that had gone into hiding after the war. Together, they were able to successfully turn Weasley's Wizard Wheezes into an enormous money-spinner again.