<prompt> Human: I did some independent work this year and calculated that I owe approximately 6k in additional taxes. I need to pay them by the 15th in order to avoid an underpayment penalty. I have the cash but if Im spending that much money, I would like to get some benefit. The IRS fees for using a credit card minimum 1.87 are approximately 115 all-in including the processing fee so any credit card I use would have to provide more benefit than the cost. Any recommendations? I currently only have airlinehotel credit card rewards cards Amex, Citi, and Chase and a Discover card that has a 1 cashback.  <response>: IRS employee here: The IRS fees for using a credit card minimum 1.87 The IRS is not charging the fee.The service provider you select is charging the fee. They would tell you the fee is for your convenience.Credit card payments are considered received when the payment is authorized. All electronic payments take about 1 - 2 weeks to record as posted, and they do so with the received date.Thank you for reading. 