There's a funny thing about the estimated $1.7 trillion that American companies say they have indefinitely invested overseas: A lot of it is actually sitting right here at home.

Some companies, including Internet giant Google Inc., software maker Microsoft Corp. and data-storage specialist EMC Corp., keep more than three-quarters of the cash owned by their foreign subsidiaries at U.S. banks, held in U.S. dollars or parked in U.S. government and corporate securities, according to people familiar with the companies' cash positions.

In the eyes of the law, the Internal Revenue Service and company executives, however, this money is overseas. As long as it doesn't flow back to the U.S. parent company, the U.S. doesn't tax it. And as long as it sits in U.S. bank accounts or in U.S. Treasurys, it is safer than if it were plowed into potentially risky foreign investments.

In accounting terms, the location of the funds may be just a technicality. But for people on both sides of the contentious debate over corporate-tax reform, the situation highlights what they see as the absurdity of rules that encourage companies to engage in semantic games, legal gymnastics and inefficient corporate-financing methods to shield profits from U.S. taxes.

The cash piling up at the nation's biggest corporations will get renewed attention in the weeks ahead, as companies report their fourth quarter and 2012 earnings. Tuesday's reports included updates from Google, which saw its stockpile of cash increase to $48.1 billion from $44.6 billion a year earlier, as well as results from Johnson & Johnson and DuPont Co.