Reminders and a simplified language help tax authorities to collect outstanding tax payments more efficiently. - Tax noncompliance harms both social cohesion and public welfare. In the US alone, tax underpayment averaged $39 billion per year from 2008 to 2010. How can tax authorities collect outstanding payments more efficiently? Novel research by RWI in cooperation with the Australian National University provides new insights: based on three natural field experiments, the researchers show that a simplified language and reminders increase tax compliance by corporate taxpayers. Early reminders are especially attractive from a tax collector's perspective.