Of course you can, the majority of British railway companies is included in the pass. Only the Heathrow express is not included I think. The UK is a great Interrail/Eurail country, you can get practically anywhere.

(London Underground, trams, busses also not included. But the Elizabeth line and London Overground are).

Enjoy your trip.

Yes, Eurail is valid on all virtually British trains. Reservations are not needed anywhere.

Exceptions are Heathrow Express, London Underground, DLR, trams and metros.

Thank you!!