This study investigates the modernization effect of the tax administration system and the law of sowing and reaping on taxpayer compliance during the COVID-19 pandemic. This study used data derived from distributing questionnaires to 100 taxpayers that have businesses located in Indonesia and embrace Christianity and Catholicism. This study used Structural Equation Modelling-Partial Least Square (SEM-PLS) for data processing. The results of this study prove that the tax administration system modernization and the law of sowing and reaping have a positive and significant impact on tax compliance during the COVID-19 pandemic.