This is a myth that the IRS already knows what everyone owes. They usually have most of your income information because it gets reported by employers and banks. They have information on some deductible expenses but not all. They often don’t have the cost basis for capital gains, so unless you want a huge tax bill, it behooves you to provide it. I didn’t fill out 15 pages of information they already have.

Yes, for 90% of the population who have one W2 and take the standard deduction, the IRS could just mail you the bill. But that was the point of my comment: don’t leave the rest of us in Intuit’s clutches!