Apple Inc. (NASDAQ:AAPL) could pay more than $28.5 billion in additional taxes on the heels of the U.S. Senate investigation into the company’s reported overseas tax dodging. This morning Wired reported that even though Apple said last week that it paid $6 billion in federal income tax in 2012, that’s not the entire story. That $6 billion amounted to only about 1/40th of all of the income tax collected from all of the nation’s corporations during all of 2012.

Apple Tax

The publication said some of Apple’s latest filings with regulators show that the company has accounted for possible future tax bills. This would enable Apple to avoid restating its earnings later if it ends up having to pay Uncle Sam additional income tax. The filings show that at the end of the company’s fiscal year, Apple Inc. (NASDAQ:AAPL) had $14.7 billion in deferred tax liabilities.

A footnote indicates Apple’s acknowledgement that it had an additional $13.8 billion in tax liabilities on income it didn’t intend on bringing back to the U.S. If Apple does end up bringing that money back into the U.S. and pays current rates on it, that tax bill would add up to at least $28.5 billion.

Meanwhile Apple Inc. (NASDAQ:AAPL) is one of several tech giants lobbying for a corporate tax amnesty holiday similar to the 2004 corporate tax holiday. Apple, Google Inc (NASDAQ:GOOG) and Microsoft Corporation (NASDAQ:MSFT) are all pushing the WIN America Campaign, a massive lobbying effort that they hope would provide them with one day in which they could bring their overseas assets back into the U.S. without carrying such a massive tax liability with it.

However such a tax holiday would have to be approved by Congress, and voters have become more aware and less tolerant of corporate offshore tax dodging practices such as the so-called “Double Irish with a Dutch sandwich,” which involves moving money through overseas markets which have lower corporate tax rates.