We are overnighting in London on our way to Italy and will stay in downtown London. I want to visit some sights the first afternoon so will need a tube ticket form Heathrow and around downtown London same day. What is the most economical tube ticket? (We arrive Heathrow at 10 AM and leave via a bus at 10 or 11 AM the next day. On our return we just need one tube ticket from Victoria to Heathrow (no overnight this time.)Thanks for advice. Julia in Vermont
From what I remember, there is no cheap way to get from the airports to the city.
As far as getting around central London, depending on how much travelling you're planning on doing, a day pass might be a good idea. You shouldn't need anything beyond Zone 1 (almost all of the attractions are in this area.)
Since you have only one day and you're wanting to do particular sight-seeing stops, it might be worth spending a little more to buy your tickets (if available) online. If you're going to the Tower, buy your tickets at a tube stop to avoid the line.
Good Luck!
For the day you arrive at Heathrow, go to the tube station at Heathrow and buy a zone 1-6 one day "off peak" travel card for 7 pounds.(Make sure you state "off peak" to save money.) It will be good on the tube, DLR and buses for unlimited travel until midnight.
For your return, just buy a single tube ticket for 4 pounds from Victoria to Heathrow (Zone 1-6).
Frank gave you great information, I have used the tube to and from Heathrow and it was great. Have a good time in London.