I've got two Oyster Cards for travel around London; they haven't been used for over five years and I believe them to be inactive.

I've read conflicting information online about how to get them reactivated. Some sites say that I will need to queue up in what could be rather long lines to get them reactivated at a ticket window. Other sites say that it can be done at a machine. Anyone have experience with this recently?

I've tried to register my card online to see if I could reactivate it that way and also add some funds. It appears that I need a UK address and phone number. Anyone ever register their card with a US address? If so, how was that done? I've tried to use a UK phone number but can't seem to get it to take.