James Gilbert, of Lewes Road, took the plastic coin dispenser and monies while a fellow passenger paid for the fare.
The driver noticed the contents were gone and suspected the people in his vehicle and challenged them.
At that point Gilbert removed the coin dispenser from his trousers and told the driver he was sorry.
Eastbourne magistrates heard how the 18-year-old then ran from the scene when the police were called.
He pleaded guilty to theft from a person at a hearing on Wednesday.
Graham Pithouse, defending, said, "He was living in a family environment but it has been necessary for East Sussex County Council to involve themselves.
"Mr Gilbert is living in supported accommodation. He is suffering from a number of issues.
"A lot of outside efforts have been going in to this young man's needs.
"He has limited resources and I would ask for a conditional discharge if you feel that is appropriate."
Magistrates gave Gilbert an 18-month conditional discharge.
No application for costs were made.