Alexander Sloley was 16 and studying accountancy at City and Islington College when he disappeared two days before his birthday in August 2008.
He had been visiting a friend’s home in Edmonton, but had set off home at around midday.
His family and friends have not heard from him since, despite issuing an efit of what he might look like in his late 20s when the police investigation was reopened in 2019.
Officers previously said he had little money, no wallet and no bag with extra clothes to indicate he was planning to run away.
When he went missing, Mr Sloley was described as a light-skinned black male, 5ft 5ins tall and of medium build, with striking blue eyes.
Detective Chief Inspector Sarb Kaur, who leads the investigation, said: “Alex was reported missing to police on 8 August 2008. Since then there have been extensive enquiries made by police but sadly Alex has not yet been found.
“We are now offering a reward of up to £10,000 for anyone who has information relating to Alex’s whereabouts.
“This remains an active missing person investigation, subject to regular review by senior officers, with the aim of locating Alex and bringing some comfort to his family.
“We have recently met with Alex’s mother to outline how we intend to progress our investigation to find him.
“I would ask anyone with information who could help to please get in contact immediately, no matter how insignificant you think this could be.
“You can contact us by calling or texting on 07860 369603.
“A dedicated incident room is staffed by experienced detectives who will handle all calls with the utmost confidentiality.
“If you prefer to remain anonymous, you can also share information through Crimestoppers.”
