Heathrow Airport to Paddington

You can use Oyster on the tube but not on the (outrageously overpriced) Heathrow Express (HEX).

From Heathrow to Paddington by Tube will require a connection, such as at Hammersmith. See the route planner at http://www.tfl.gov.uk/. Heathrow Express train tickets cost about $30 or are covered by most BritRail passes, which is a good option if you're using a pass to catch the next train connection at Paddington.

Bus to Hayes and Harlington, train from there to Paddington for Oyster - if you don't have too much luggage. Quicker than the Underground option.

Heathrow Express is £25 round trip each if there are two of you and book in advance.

If you want to use train transportation, you can use Heathrow Connect for half the price of the Express. It takes a little longer and makes a few stops along the way. I don't recommend the Connect early in the morning at commute times. The trains get extremely crowded one or two stops along the way. There is literally no room for luggage without displacing people. I haven't used the bus on this route.

I just bought tickets for Heathrow Connect via internet: www.heathrowconnect.com. The tickets were 10.10 GBP each, one way. I have a claim number to pick up the physical tickets at the airport. It was a very easy process.

I am curious whether there is any price advantage to buying Heathrow Connect tickets in advance online vs. buying at the airport when we arrive. We are scheduled to land at approx. 8:30am and we have no time table for arriving at Paddington station. We will purchase return tickets at the same time, as we are planning to use Heathrow Connect to return to the airport for our departure midday on a Saturday.

There is no price advantage buying in advance and tickets need to be collected from the machines. If you have some kind of a Railcard though and are looking for the discount, you have to buy the tickets from the office

Thank you for the information Marco.