Evaluation of E-Government Service Delivery and Citizen Satisfaction at the Federal Inland Revenue Service Online Portal in Abuja, North Central Nigeria

E-government portals are intended to improve service delivery efficiency and citizen satisfaction by enabling remote access to government services, yet the usability and performance of these platforms in Nigeria remain underexplored from the citizen perspective. This study evaluates the quality of e-government service delivery and its relationship with citizen satisfaction at the Federal Inland Revenue Service online portal in Abuja, North Central Nigeria. A descriptive survey was administered to 250 registered taxpayers who had used the FIRS e-service portal within the preceding three months, selected through convenience sampling at two FIRS service centres in the Federal Capital Territory. The WebQual 4.0 instrument adapted for the Nigerian context assessed usability, information quality, service interaction quality, and overall satisfaction. Descriptive statistics and regression analysis were computed using SPSS. Available e-government literature from North Central Nigeria identifies session timeout errors, inadequate feedback mechanisms, and limited multilingual support as the most frequently cited usability barriers in Nigerian government portals. The DeLone and McLean IS Success Model provides the evaluative framework. Findings indicate that information quality and service interaction quality are the strongest predictors of overall citizen satisfaction, together explaining 61 percent of variance. The study recommends regular usability audits, citizen feedback integration into portal redesign cycles, and FIRS staff training in digital service management. Keywords: e-government, FIRS portal, citizen satisfaction, service delivery, Abuja.