The US Internal Revenue Service (IRS) is seeking an additional tax payment of $28.9 billion plus penalties and interest from Microsoft, the US-headquartered global software giant disclosed on Wednesday night, adding that it would appeal the claim.  “The main disagreement is the way Microsoft allocated profits during this time period among countries and jurisdictions. This is commonly referred to as transfer pricing and the IRS has established regulations that allow companies to use a specific arrangement for transfer pricing, called cost-sharing,” the group’s corporate vice president for worldwide tax and customs Daniel Goff wrote in a company blog post. He…