Salle, I.Z., Winarsih , A.R. , Winarti, W. and Azis , N.A. 2026. Harmonization of PPh 21 Calculations Before and After the Implementation of The Average Effective Rate for Employees of PT. Fisca Bisnis Solusi: JEL Classification: H24, H25, H26, K34, M41. Journal of Management and Administration Provision . 6, 2 (Jun. 2026), 338-356. DOI:https://doi.org/10.55885/jmap.v6i2.955.