The Human Capital paradigm, used as a catalyst for digital transformation, aims to increase the company's competitive value. The paradigm is outlined in the form of a Digital Human Capital Information System (HCIS) to support digital transformation at PT XYZ. However, this implementation raises a gap with legacy systems that have been running before, so data integration between the two systems is needed. This study aims to determine the critical success factor (CSF) of data integration in HCIS implementation. This study uses the HOT-fit model and TOE framework to determine the factors that influence the success of implementation, then the analytical hierarchy process (AHP) is used to determine the factor that has the greatest influence. The results found that these factors are classified into four criteria: human, technology, organization, and environment. Among the four criteria, the environment is the most important criterion, followed by human, technology, and organization. CSF in each criterion are government regulations and support, innovativeness of senior executives, perceived compatibility, and relative advantage.