Often when people learn about accord and satisfaction they wonder whether someone could use it to pay off a credit card. As the book makes clear that won't work since there are safeguards in terms of who you need to send it to. But the other issue is that credit card debt is generally liquidated - there is no real dispute about how much is owed. Unliquidated debts are actually pretty uncommon - try to come up with an example that doesn't involve disputes about medical billing