Heidi Agan, a 32-year-old mother-of-two, is constantly mistaken for the Duchess, in fact even her three-year-old daughter can't tell the two women apart.
She was earning 6 pounds an hour when she quit her job as a waitress at her local Frankie and Benny's to become Kate lookalike and now she's earning 650 pounds a day, the Daily Mail reported.
"People would come in and point at me and say 'that's her'," Agan said.
"I've had other people come up to me during jobs convinced I'm Kate. When my daughter sees her in a magazine she points and says, 'there you are mummy'," she said.
"She's turned into a right little royalist," she said.
She joined London-based agency Susan Scott Lookalikes in February and has stocked up on some of the Duchess's most memorable dresses, including the blue Issa dress she wore as she and Prince William announced their engagement, as well as her favourite shoes and accessories.
However Agan said she won't be following Kate's lead by being caught topless.
"I felt really bad for Kate when the photos were published as she was on a private trip with her husband," Agan said.
Agan, who lives in Corby, Northamptonshire, with a son and a daughter, said the strangest request she's had so far is to play a game of Twister with lookalikes of Prince William and the Queen for a photo-shoot.