Rhys McLennan, 19, was behind the wheel of a Nissan Pixo when it hit a tree on the B6341 near Edlingham, close to Alnwick, in October 2020.
McLennan’s passenger, Chelsea Gillie, 17, from Berwick suffered serious injuries.
She was taken to the RVI but died three days later with her family at her bedside.
McLennan, who was 18 at the time of the accident, was also taken to hospital, but was not badly hurt. Chelsea was just a few months off her 18th birthday.
At Newcastle Crown Court today, McLennan, of Cheviot Lodge in Longframlington, admitted causing death by careless driving, causing death by driving a vehicle while unlicensed and causing death by driving a vehicle while uninsured.
The case was adjourned until August 5 so a pre-sentence report can be prepared by the probation service.
Judge Penny Moreland granted McLennan bail in the meantime, but warned him: "Please do not assume you will get a non-custodial sentence because I am granting you bail and directing the report.
"All options remain open to the judge who passes sentence."
In a statement released shortly after Chelsea’s death, her devastated family said she would be sorely missed. They added: “Chelsea was a daughter, sister and friend who was taken too soon from all those who loved her.
“She had her whole life ahead of her. Sleep tight and rest in peace baby girl.”