Heathrow Express
Bombardier Transportation at Ilford Depot had modified twelve of these trains by December 2020, installing new first-class seating, Wi-Fi, luggage racks and on-board entertainment, to be used on Heathrow Express services. Rebranded as "Heathrow Express", and refurbished with Heathrow Express moquette, they replaced the existing , entering service on 29 December 2020.