We quantify the intended and unintended consequences to firms of increasing tax information disclosure to the IRS. Our empirical strategy leverages an exogenously staggered adoption of a redesigned tax form. We find that the redesign was successful at increasing compliance after 2011 among some firms, the intended consequence. At the same time, we find that firms changed their reporting in a way that decreased expected tax liability, an unintended consequence. We estimate that this unintended behavior reduced corporate receipts by $1.3 billion.