Many more were injured when carriages carrying 69 people derailed near Sandilands stop back in 2016.
Transport for London was fined £10 million and Tram Operations Limited will have to pay £4 million after both accepted failings in their health and safety duties.
49 year old tram driver Alfred Dorris was cleared of health and safety offences by a jury at the Old Bailey in June.
61 passengers were also injured, and of those, 21 were seriously hurt or sustained life-changing injuries.