In the context of the overpayment of benefits, this systematic map aims to describe existing research literature on the process of notifying a change of circumstance (CoC) in the fields of financial products and services, welfare provision, taxation and tax credit systems. This systematic review was published by EPPI-Centre in 2011. Systematic reviews aim to find as much as possible of the research relevant to the particular research questions, and use explicit methods to identify what can reliably be said on the basis of these studies.