The purpose of this study is to validate an extended integrated model of e-filing continuance usage. The base model, which has its theoretical basis in the IS Success Model and Expectancy-Confirmation Model (ECM), is extended by including three moderators: tax complexity, prior experience with other e-government services, and perceived risk. The data collected from 300 e-filing users in the Philippines. Hypotheses were tested using PROCESS Macro for SPSS. Results suggested that tax complexity has a moderating effect on the relationship between system quality and satisfaction, while perceived risk has a moderating effect on the relationship between satisfaction and continuance intention.