Hannah Tointon has revealed she and sister Kara Tointon worried about auditioning for Mr Selfridge together in case only one of them got the part.
The Inbetweeners star Hannah, 27, and her older sister Kara, 31, have both been cast in the ITV drama as Harry Selfridge's daughters Violette and Rosalie in the third series, set five years on from the last series.
Hannah revealed: "I got the call that I had this audition for Mr Selfridge and then Kara got the call that she was going for Mr Selfridge - and I thought it was for the same part, so I was a bit... But Kara knew it was for sisters.
"We've always wanted to not do anything together because we've never really wanted to cross over that boundary, we like to keep our private life private and then our work life separate.
"But then we were like, 'You go for it, no you go for it', and then somebody said why are you being so pathetic, it's for sisters and actually it might be really nice.
"And so we both went for the part and then we were just worried one of us would get it and the other one wouldn't. We didn't care if we both didn't get it.
"But actually it was nice when we got both got the call, and the first day on set it was so great we didn't know what we were worrying about, it's lovely."
Hannah's character Violette is very headstrong, like her father, and often clashes with Harry (Jeremy Piven) while Kara's character Rosalie is the sensible sister and fits into the role of the mother figure.
Hannah said of her and Kara's own personalities: "We're different like that. She is very sensible in some ways, but then in other ways, I'm the one telling her what to do, and giving her advice. So I would say in different scenarios, our different personalities come out.
"But we are very different. I'm very like Violette in some ways, in that I know my mind and I can sometimes be a bit stubborn. But I'm not as crazy or rebellious as her by any means."
Mr Selfridge returns to ITV on Sunday January 25.