Official Payments Corp., which I am only using as an example, says that it handles state income tax payments for 26 states. (Nine states have no personal income tax.) Their list includes the largest ones. It works the same way as paying your Federal tax bill in terms of using a credit card and adding a fee. There are other firms that offer this type of service as well. Some of them may also work with some of the 15 states that OPC doesn't cover.