1. (a) For all taxable years beginning before January 1, 1985, the corporate tax rate is four percent (4%).
2. (b) For all taxable years beginning after December 31, 1984, the corporate tax rate is five percent (5%).
3. (c) For all taxable years beginning after December 31, 1989, the corporate tax rate is six percent (6%).
4. (d) For all taxable years beginning after December 31, 2021, the corporate tax rate is four percent (4%).

Amended at 39 Ok Reg 2249, eff 9-11-22