Over the years, tax administration in Nigeria has been plagued with several limiting factors such as weak administrative lapses and weak administrative facilities like the evidence of manually compiled database of tax payers. ICT was however identified as a solution to addressing most of the limiting issues of tax administration. The study examines the effect of ICT on tax administration in FIRS, Jos. The Technology acceptance Model(TAM by Davis, 1989) was used to underpin the study. The study adopted survey research design, where both primary and secondary data were used. The primary source of data were questionnaires and interviews while secondary data was obtained from "FIRS Guage": A quarterly publication of FIRS, Handbook of FIRS among others. Quantitative data was analyzed using frequency counts and percentages, while chi-square was used to test the hypotheses. Data generated through interview was analyzed qualitatively. The study established that there are adequate ICT infrastructures in FIRS, Jos. The study also revealed that ICT capacity of staff of FIRS is adequate as all 70 staff of FIRS have been trained on basic ICT skills. From findings of the study, we therefore concluded that ICT has enhanced performance in revenue administration by reducing human error and processing times, providing readily accessible data for tax officers and facilitating better decision making by tax authorities. Hence the study recommended among others that FIRS should ensure an improved ICT infrastructure which includes completion of the fibre-optic network project, because without a robust ICT infrastructure, the modernization project would not be achieveable.