The boy, 17, was arrested in Norwich on November 3 last year.
On Thursday he was accused of seven counts of offences against the Computer Misuse Act 1990 during October 2015 following an investigation by detectives from the Metropolitan Police’s Cyber Crime Unit.
The telecoms giant said it had been subjected to a ‘significant and sustained’ attack on its website on October 21, which prompted fears that millions of people may have had their bank details stolen.
It has since said the data hacked was ‘significantly less than originally suspected’, with fewer than 21,000 unique bank account numbers and sort codes accessed.
The teenager has been released on bail to appear at Norwich Youth Court on October 18.