This quantitative study aims to determine the significant relationship of the respondents’ profile and the indicators such as functionality, reliability, efficiency, usability, maintainability and portability of the Internal Revenue Integrated System (IRIS) of the Bureau of Internal Revenue. The research instrument includes the demographical profile question for the respondents includes their age and years in service at the Bureau of Internal Revenue. It includes 57 questions and a 5-point Likert scale and the research instrument is based on the ISO 9126 Software Engineering Standard was administered to the 41 frontliners of Revenue District No. 55 – San Pablo City. Findings of the study conclude and shows that there is no significant relationship in the profile of the respondents which is the age and years in service compare to the indicators of the Internal Revenue Integrated System (IRIS) such as functionality, reliability, usability, efficiency, maintainability and portability. Using the mean the result shows that the system has an average of moderately to very acceptable verbal interpretation. Spearman rho was used to test the significant relationship between respondents’ profile and the indicators of the Internal Revenue Integrated System (IRIS). This information can be used to help the Bureau of Internal Revenue on how to enhance the system without affecting business registration processes and services.