One of the distinctive, visceral terrors of American maturity is getting a letter with “Internal Revenue Service” on the return deal with. Just ask Microsoft’s accounting division. According to an SEC submitting dated October eleventh, the corporate acquired an overdue tax invoice from the IRS for an unimaginable $28.9 billion (with a “b”) {dollars}. Microsoft will battle the adjusted invoice, to the shock of completely nobody.

According to a blog post attached to the filing written by Microsoft vp Daniel Goff, the IRS arrived on the startling determine after auditing the corporate’s company returns for the years between 2004 and 2013. The core of the adjustment is, quote, “the way Microsoft allocated profits during this time period among countries and jurisdictions.”

International firms like Microsoft usually transfer revenue and earnings amongst places of work in a number of nations to attempt to discover probably the most favorable tax legal guidelines. While the observe is pretty common at Microsoft’s stage, wading into the usually conflicting world of tax regulation can result in accusations of tax avoidance. Ireland is taken into account a semi-legal tax haven for such functions, and Microsoft has in depth company places of work in Dublin, together with its rivals Apple, Google, and Facebook.

Though Microsoft is likely one of the world’s largest tech firms with a market cap of greater than two trillion {dollars}, $29 billion would nonetheless signify an enormous hit to its earnings. For the sake of comparability, the corporate’s acquisition of sport writer Activision-Blizzard has a proposed value of $68.7 billion.

Goff didn’t present a extra exact breakdown of the IRS Notices of Proposed Adjustment, however stated that the corporate will attraction the invoice beginning with $10 billion in potential rebates from the Tax Cuts and Jobs Act of 2017, which considerably minimize the tax charge for the biggest American firms. Microsoft has already promised to attraction the choice and go to courtroom if the IRS received’t relent, a course of that might take years.