Originally Posted by mdbe

I believe not accepting intl cards online is against the merchant agreement as well. The first company I got my car insurance with in the US would not accept the payment with a non-US issued card online or over the phone. I filed a complaint online with Visa and Amex, as well as had my issuing bank reach out to Amex. Lo and behold, received a call a week later apologizing for their "system issues", and the payment was processed promptly. I've yet to encounter another merchant in the US, in Europe or online, that has an issue with an intl issued card.