Around 90 buses have been taken out of use as a precautionary measure while the company investigates the cause of the fire.
TfL has taken the entire vehicle fleet out of passenger service, causing disruption to around five routes.
Bus operators are moving vehicles form other garages to serve the impacted routes and are searching for more buses they can put into service to minimise the disruption to passengers.
The buses involved are electric and so it is thought that the battery could have been at fault.
Taking the buses out of service is routine when a major fire occurs for the safety of passengers.
A TfL spokesperson said: “As a precaution, Switch Mobility has asked all operators that use its double decker electric buses to temporarily withdraw them from service while it conducts an investigation and carries out safety checks.
“We have arrangements in place to minimise any disruption on the routes where these buses operate.
“We apologise to any customers who are experiencing disruption to their bus service.”