This Digest looks at birth registration, a fundamental human right that opens the door to other rights, including education and health care, participation and protection. It explains why the births of more than 50 million babies go unregistered every year. In legal terms, these children do not exist and their right to an official name and nationality is denied. Their access to basic services may be severely jeopardised and they may find themselves more vulnerable to abuse and exploitation. The effects can last a lifetime, with the unregistered adult unable to vote, open a bank account or obtain a marriage licence. Non-registration also has serious implications for the State. Put simply, countries need to know how many people they have and how many there are likely to be in the future, in order to plan effectively. This Digest emphasizes the crucial importance of birth registration, explores the obstacles to universal registration and highlights the actions - including awareness raising, legislative changes, resource allocation and capacity building - that are needed to ensure the registration of every child.