Free London Underground services and shuttle trains (Elizabeth Line and Heathrow Express) are available for inter-terminal transfers between Heathrow Terminals 2&3 and Heathrow Terminal 5.
How long does it take to transfer from Heathrow Terminal 3 to 5?
Between Terminal 3 and Terminal 5: 90 minutes. Within Terminal 5 (UK domestic and international flights): 60 minutes.