Identifying everyone residing in a country, especially the poor, is an indispensable part of pursuing universal health coverage (UHC). Having information on an individuals' financial protection is also imperative for measuring the progress of UHC. This paper examines different ways of instituting a system of unique health identifiers that can lead toward achieving UHC, particularly in relation to utilizing universal civil registration and national unique identification number systems. Civil registration is a fundamental function of the government that establishes a legal identity for individuals and enables them to access essential public services. National unique identification numbers assigned at birth registration can further link their vital event information with data collected in different sectors, including in finance and health. Some countries use the national unique identification number as the unique health identifier, such as is done in South Korea and Thailand. In other countries, a unique health identifier is created in addition to the national unique identification number, but the two numbers are linked; Slovenia offers an example of this arrangement. The advantages and disadvantages of the system types are discussed in the paper. In either approach, linking the health system with the civil registration and national identity management systems contributed to advancing effective and efficient UHC programs in those countries.