Most Tube station ticket machines are only accepting bank cards. You can top up using your contactless and Oyster account, the TfL Oyster and contactless app or an Oyster ticket stop. Ticket machines at all London Overground and DLR stations are still accepting cash.
Piccadilly Line: A 10 minute service is operating between Acton Town and Uxbridge, A 5 minute service is operating between Cockfosters and Heathrow Airport due to operational restrictions. Public transport should only be used for essential journeys.