Reece Scobie, 20, who has Asperger's Syndrome and obsessive compulsive disorder, is currently serving 16 months for an earlier crime, in which he conned travel agents out of more than £70,000 for flights and stays in hotels used by celebrities.
But the Scot, from Rait, Perthshire, was back in court yesterday after he admitted using stolen credit cards to book trains, flights and hotels online.
At Southwark Crown Court Judge John Price said: "You are 20. You have got Asperger's. You are having a lonely time in prison.
"If you don't learn now, you never will."
He locked Scobie up for eight months to be served consecutive to his Scottish prison term.