I'm somewhat nonplussed by this:
In a program aimed at individual taxpayers who lack checking accounts or credit cards, the IRS has unveiled a partnership with retail stores (currently only 7-Eleven) to allow these taxpayers to pay their federal tax bill in cash (IR-2016-56). Called PayNearMe, taxpayers can pay up to $1,000 a day at over 7,000 participating stores for a $3.99 fee. The IRS says that many of the stores are open 24 hours a day, 7 days a week.
I don't necessarily recommend walking around with $1,000 in cash to pay your taxes but whatever works. Plus: Slurpee!