Heathrow and Travelcard

1. Last time I checked, the 7 day pass was the best choice for any visit 4 days to 7 days. This can be a paper card or an Oyster card.

2. I've never used the 2 for 1 pass so check my comment (or someone will correct). I think you need to have a travel card for that specific day for a 2 for 1 pass. I don't think a 7 day pass can be used so you'd have to buy one each day you want to do a 2 for 1. I'm not sure if Oyster cards or paper passes are available at Heathrow.

3. Search the web.

4. You can order a 7 day card in advance and it will be mailed to you. The zone 1-2 pass couldn't be used getting from Heathrow into London. I ordered one once and a paper pass arrived. You can't add extra cash onto the paper card (subject to correction by knowledgeable locals).

5. I've used the "slow" train to Paddington. Buying a round trip is a little cheaper. You can buy an Oyster card there.

6. You can either get the 7 day pass or pay as you go. Neither way will make enough difference to matter in your overall trip cost. If you are actually staying around Victoria Station, I'd take the tube and buy an oyster card (if available) at Heathrow with a little extra for the outside zone travel or just a one way ticket. I'd go back the same way. It will take longer than the train but probably not much different than taking the tube to Paddington and then switching to a train.

You are right on 1, 2 and 4. If you want to use the 2-for-1 offers, then you do need a paper travel card purchased at a rail station ticket window. A 7-day card is fine since it will be dated for the full 7 day time frame and the requirement is just that you have a travel card valid for that day. You will also need the vouchers for the sites you're visiting. They're available at the rail stations or at www.daysoutguide.co.uk. (3) The best station (5) is the one most convenient to where you are staying. "Best" way (6) is also dependent on where you're staying. Heathrow Express is fast, but not cheap, to Paddington Station, but if you have to hop on the Tube for some distance after that, it cuts down on the speed of the journey. Usually the cheapest way is the Tube, but if you have a 4 people or more in your group, then some people recommend a car service like Just Airports as a good balance of time/cost/convenience. We have not used them, (we just take the Tube) but are considering them for our next trip.

You don't need to go to Paddington to get the 7-day travelcard - any railway station operated by National Rail not London Overground should be able to do it for you, so somewhere else might be more convenient to wherever you are staying. A photocard is needed for this ticket so bring along a passport sized photo for this.