In the early hours of June 13 the pair stole a D3 single-decker bus from the Henley Road garage in Silvertown.
After taking it on a joyride they crashed into two parked cars, a BMW and a Kia.
They then returned to the same garage hours later to steal a double-decker bus which they then crashed into the garage fencing.
One of the boys, who is from Bexley borough, will be sentenced this week after he admitted taking a vehicle without consent, as well as driving without insurance or a licence.
The other boy, from east London, pleaded guilty to two counts of aggravated vehicle taking, and driving without insurance or a licence.
He was sentenced to a 12-month youth referral order in August.
Rosie Trew, TfL’s Head of Bus Service Delivery, said in a statement: “Together with London’s bus operators, we take safety and security across our network extremely seriously.
“We are working with the operator of this bus garage, Go-Ahead, to ensure that all appropriate security measures are in place and to prevent an incident such as this occurring again.”
