Originally Posted by
aamilesslave
I think there is a euro threshold on the machines that requires a card with a chip. I was always able to use my US credit card to purchase a one-way trip to the airport or a carnet of metro tickets. I think I could even purchase a 1-week Carte Orange with my US credit card. However, I was never able to purchase a 1-month Carte Orange with my US credit card at the machines.
No, I don't think so. Over time I've tried to buy carnets from machines at various metro stations with a US credit card, and it's worked at some but not at others (for example, worked at Boissière but not at Vaugirard or rue du Bac).
Separate machines are used to recharge the Navigo passes but I've never tried a US credit card in any of those.