I sometimes pay with an AmEx-Card, but to keep track I have a seperat account where I store the money so I don't get surprised when the bill arrives once a month. Sadly, you cannot Include those Payments in your Budget.
Same applies if you put aside let's say 200 a month, I know the money is technically not gone, but if you want to stay under a certain amount, would be nice to include that in your total monthly Budget