Floyd Mayweather's issues with the IRS are no joke.

He currently owes Uncle Sam $22.2 million, and it's been suggested the only reason he's fighting Conor McGregor is to pay off his debt.

[Related: Floyd Mayweather posts tax bill amid talk he needs to fight to pay IRS.]

Deadspin did a deep dive into Money's financial records and found that Mayweather has a history of running up huge tax bills.

It came out recently that Floyd Mayweather owes the IRS a whopping $22.2 million, but documents show that that big number is the least of it. The famous boxer—who routinely brags about his wealth, and even goes by the nickname “Money”—has had trouble paying his taxes on time for more than a decade. The IRS has filed more than two dozen pages of tax liens (and releases from those liens) in the boxer’s name in Clark County, Nev., since 2004," Deadspin reports. "At various points, according to lien documents, he has owed $3.1 million, $6.1 million, and $7.1 million to the feds. Mayweather has taken in millions in earnings and owned his own promotional company, dubbed “The Money Team,” but that hasn’t kept him from running up enormous tabs, some of which have gone unpaid, according to public records.

"Floyd’s a savvy investor and if he is investing money and getting a rate of return that far exceeds what he has to pay the IRS in interest, then any smart business person is going to take advantage of that deferral. So Floyd’s looking at this and saying this is a better business decision to just defer my taxes until it’s the best time for me to pay it. So we’ve taken advantage of that," Mayweather’s tax lawyer, Jeffrey Morse, explains."

In the past, Mayweather could square things with the IRS by scheduling another fight. But, at 40, Floyd can't do that for too much longer.

Which probably means he's going to have cut down on his spending, lest he end up like his (sometimes) good buddy 50 Cent.