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INCOME TAXES - Reconciliation of Federal Statutory Income Tax Rate (Details) | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Reconciliation of federal statutory income tax rate to effective income tax rate |  |  |
Federal statutory rate | 21.00% | 21.00% | 21.00%
State income tax, net of federal deduction | 3.60% | 2.90% | 7.80%
Changes in valuation allowance, net of federal benefit | 1.90% | (0.30%) | (1.60%)
Employee stock plans' dividend deduction | (0.40%) | (0.50%) | (0.50%)
Non-deductible book depreciation | 0.60% | 0.70% | 0.60%
Flowback of excess deferred income taxes | (3.90%) | (9.20%) | (6.60%)
AFUDC-Equity | (0.80%) | (1.10%) | (1.10%)
Federal PTCs | (2.80%) | (1.20%) | 0.00%
ITC amortization | (1.20%) | (1.30%) | (1.30%)
Noncontrolling interests | 0.60% | 0.60% | 0.50%
Other | (0.10%) | (0.20%) | 0.00%
Effective income tax (benefit) rate | 18.50% | 11.40% | 18.80%
Alabama Power |  |  |
Reconciliation of federal statutory income tax rate to effective income tax rate |  |  |
Federal statutory rate | 21.00% | 21.00% | 21.00%
State income tax, net of federal deduction | 5.00% | 5.20% | 4.80%
Changes in valuation allowance, net of federal benefit | 0.00% | 0.00% | 0.00%
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00%
Non-deductible book depreciation | 0.60% | 0.70% | 0.50%
Flowback of excess deferred income taxes | (5.30%) | (19.80%) | (1.90%)
AFUDC-Equity | (0.70%) | (1.20%) | (0.80%)
Federal PTCs | (0.10%) | 0.00% | 0.00%
ITC amortization | (0.10%) | (0.10%) | (0.10%)
Noncontrolling interests | 0.00% | 0.00% | 0.00%
Other | 0.00% | (0.20%) | 0.30%
Effective income tax (benefit) rate | 20.40% | 5.60% | 23.80%
Georgia Power |  |  |
Reconciliation of federal statutory income tax rate to effective income tax rate |  |  |
Federal statutory rate | 21.00% | 21.00% | 21.00%
State income tax, net of federal deduction | 1.70% | 2.10% | 3.30%
Changes in valuation allowance, net of federal benefit | 3.10% | (0.60%) | 3.20%
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00%
Non-deductible book depreciation | 0.70% | 0.80% | 0.60%
Flowback of excess deferred income taxes | (2.20%) | (2.60%) | (9.60%)
AFUDC-Equity | (1.00%) | (1.20%) | (1.50%)
Federal PTCs | (3.70%) | (1.40%) | 0.00%
ITC amortization | (0.20%) | (0.10%) | (0.10%)
Noncontrolling interests | 0.00% | 0.00% | 0.00%
Other | (0.20%) | (0.30%) | 0.00%
Effective income tax (benefit) rate | 19.20% | 17.70% | 16.90%
Mississippi Power |  |  |
Reconciliation of federal statutory income tax rate to effective income tax rate |  |  |
Federal statutory rate | 21.00% | 21.00% | 21.00%
State income tax, net of federal deduction | 4.40% | 4.90% | 4.40%
Changes in valuation allowance, net of federal benefit | 0.00% | 0.00% | 0.00%
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00%
Non-deductible book depreciation | 0.30% | 0.40% | 0.30%
Flowback of excess deferred income taxes | (6.50%) | (10.20%) | (7.80%)
AFUDC-Equity | 0.00% | 0.00% | 0.00%
Federal PTCs | 0.00% | 0.00% | 0.00%
ITC amortization | 0.00% | 0.00% | 0.00%
Noncontrolling interests | 0.00% | 0.00% | 0.00%
Other | 0.00% | 0.10% | 0.30%
Effective income tax (benefit) rate | 19.20% | 16.20% | 18.20%
Southern Power |  |  |
Reconciliation of federal statutory income tax rate to effective income tax rate |  |  |
Federal statutory rate | 21.00% | 21.00% | 21.00%
State income tax, net of federal deduction | (2.30%) | (0.70%) | 1.90%
Changes in valuation allowance, net of federal benefit | 0.00% | 0.00% | 0.00%
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00%
Non-deductible book depreciation | 0.00% | 0.00% | 0.00%
Flowback of excess deferred income taxes | 0.00% | 0.00% | 0.00%
AFUDC-Equity | 0.00% | 0.00% | 0.00%
Federal PTCs | (17.20%) | (7.40%) | (6.60%)
ITC amortization | (26.40%) | (19.00%) | (17.20%)
Noncontrolling interests | 17.10% | 11.10% | 8.40%
Other | 0.20% | 0.10% | (0.10%)
Effective income tax (benefit) rate | (7.60%) | 5.10% | 7.40%
Southern Company Gas |  |  |
Reconciliation of federal statutory income tax rate to effective income tax rate |  |  |
Federal statutory rate | 21.00% | 21.00% | 21.00%
State income tax, net of federal deduction | 7.00% | 7.80% | 6.40%
Changes in valuation allowance, net of federal benefit | 0.00% | 0.00% | 0.00%
Employee stock plans' dividend deduction | 0.00% | 0.00% | 0.00%
Non-deductible book depreciation | 0.00% | 0.00% | 0.00%
Flowback of excess deferred income taxes | (2.20%) | (2.60%) | (2.50%)
AFUDC-Equity | 0.00% | 0.00% | 0.00%
Federal PTCs | 0.00% | 0.00% | 0.00%
ITC amortization | 0.00% | 0.00% | (0.10%)
Noncontrolling interests | 0.00% | 0.00% | 0.00%
Other | 0.00% | (0.60%) | (0.90%)
Effective income tax (benefit) rate | 25.80% | 25.60% | 23.90%

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