I assume that many people would think charging the taxes owed on a credit card would be foolish. Here is what I do.
I have a Fidelity 2% cash back Visa card. I can charge my taxes on my Visa card at pay1040.com. They charge 1.87%. "The convenience fee for this service is 1.87% of the tax payment amount for credit cards"
If I charge $5,000, I get two charges on my credit card. One for $5,000.00 and another for $93.50. I get 2% back from the $5,000 charge, or $100. I also get 2% back from the $93.50 charge, or $1.87. Total tax free money I just made is (($100 + $1.87) - $93.5) = $8.37.
A bit over $8 is not enough to get too excited over, but it is a free $8. Do it 4x a year, and it is $33.48. Most millionaires never made a million dollars at one time. People make a million a few cents or dollars at a time.