They'll tell you, if you file a FOIA request. But then the documents they send are poorly documented, and very difficult to extract the required information fr

They'll tell you, if you file a FOIA request. But then the documents they send are poorly documented, and very difficult to extract the required information from. The documents you want might also arrive after the annual filing deadline, or never. And what they calculate for what you owe never includes optional means of reducing tax owed. So in some cases, the number you calculate for yourself can be both lower than theirs and yet still correct. If you are in a business that includes a lot of cash transactions, or have to report additional income from sources that do not automatically report on a 1099 or w2, a FOIA request should be able to tell you what the IRS already knows about, and can prove that you earned. That will allow you to calculate how many patriotic brownie points you will earn for reporting those sources that aren't already noted in your file. As with many things related to government administration, be warned that if you choose to play stupid games, you might win stupid prizes.