Hopefully you don’t owe the IRS $100 million or more, but those who do will need to plan on paying with something other than a check after December 31st. Internal Revenue Bulletin No. 2015–36, dated September 7, 2015, states:
“The Federal Reserve will not accept checks that are larger than $99,999,999.00 and agencies have been directed to return these checks to the originator. Beginning January 1, 2016, IRS will begin returning checks for more than $99,999,999.00 to the originator.”
But the IRS isn’t just trying to be difficult. As it turns out, no check processing equipment can handle checks over $100 million, so they are handled manually. And there are just too many chances for mistakes or misplacement with manual check processing. The IRS is still accepting credit card payments for amounts over $100 million.