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INCOME TAXES (Tables) | 12 Months Ended
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Dec. 31, 2023
Income Tax Disclosure [Abstract] |
Details of income tax provisions | Details of income tax provisions are as follows:
| 2023
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Power | Southern Company Gas
| (in millions)
Federal — |  |  |  |  |  |
Current | $ | 54 |  | $ | 242 |  | $ | 205 |  | $ | 49 |  | $ | (320) |  | $ | 62 |
Deferred | 299 |  | (257) |  | 195 |  | (26) |  | 334 |  | 68 |
Total federal | 353 |  | (15) |  | 400 |  | 23 |  | 14 |  | 130 |
State — |  |  |  |  |  |
Current | 41 |  | 82 |  | 37 |  | 1 |  | (1) |  | 24 |
Deferred | 102 |  | 14 |  | 11 |  | 12 |  | (1) |  | 57 |
Total state | 143 |  | 96 |  | 48 |  | 13 |  | (2) |  | 81 |
Total | $ | 496 |  | $ | 81 |  | $ | 448 |  | $ | 36 |  | $ | 12 |  | $ | 211 |
| 2022
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Power | Southern Company Gas
| (in millions)
Federal — |  |  |  |  |  |
Current | $ | 10 |  | $ | 54 |  | $ | 38 |  | $ | 42 |  | $ | (43) |  | $ | 122 |
Deferred | 455 |  | 259 |  | 152 |  | (16) |  | 56 |  | (3) |
Total federal | 465 |  | 313 |  | 190 |  | 26 |  | 13 |  | 119 |
State — |  |  |  |  |  |
Current | 27 |  | 14 |  | (21) |  | — |  | 2 |  | 42 |
Deferred | 303 |  | 96 |  | 201 |  | 11 |  | 5 |  | 19 |
Total state | 330 |  | 110 |  | 180 |  | 11 |  | 7 |  | 61 |
Total | $ | 795 |  | $ | 423 |  | $ | 370 |  | $ | 37 |  | $ | 20 |  | $ | 180 |
| 2021
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Power | Southern Company Gas
| (in millions)
Federal — |  |  |  |  |  |
Current | $ | 50 |  | $ | 104 |  | $ | 311 |  | $ | 25 |  | $ | (340) |  | $ | 85 |
Deferred | 36 |  | 172 |  | (449) |  | (15) |  | 343 |  | 35 |
Total federal | 86 |  | 276 |  | (138) |  | 10 |  | 3 |  | 120 |
State — |  |  |  |  |  |
Current | (25) |  | 23 |  | 71 |  | — |  | (16) |  | (68) |
Deferred | 206 |  | 73 |  | (101) |  | 11 |  | — |  | 223 |
Total state | 181 |  | 96 |  | (30) |  | 11 |  | (16) |  | 155 |
Total | $ | 267 |  | $ | 372 |  | $ | (168) |  | $ | 21 |  | $ | (13) |  | $ | 275 |
Summary of amortization of tax credits | ITCs amortized in 2023, 2022, and 2021 were immaterial for the traditional electric operating companies and Southern Company Gas and were as follows for Southern Company and Southern Power:
| Southern Company | Southern Power
| (in millions)
2023 | $ | 84 |  | $ | 58 |
2022 | 83 |  | 58 |
2021 | 84 |  | 58 |
Schedule of effective income tax reconciliation | A reconciliation of the federal statutory income tax rate to the effective income tax rate is as follows:
| 2023
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Power | Southern Company Gas
Federal statutory rate | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | %
State income tax, net of federal deduction | 2.6 |  | 5.2 |  | 1.5 |  | 4.9 |  | (0.7) |  | 7.8 |
Employee stock plans' dividend deduction | (0.5) |  | — |  | — |  | — |  | — |  | — |
Non-deductible book depreciation | 0.7 |  | 0.7 |  | 0.8 |  | 0.4 |  | — |  | — |
Flowback of excess deferred income taxes | (9.2) |  | (19.8) |  | (2.6) |  | (10.2) |  | — |  | (2.6) |
AFUDC-Equity | (1.1) |  | (1.2) |  | (1.2) |  | — |  | — |  | — |
Federal PTCs | (1.2) |  | — |  | (1.4) |  | — |  | (7.4) |  | — |
ITC amortization | (1.3) |  | (0.1) |  | (0.1) |  | — |  | (19.0) |  | — |
Noncontrolling interests | 0.6 |  | — |  | — |  | — |  | 11.1 |  | — |
Other | (0.2) |  | (0.2) |  | (0.3) |  | 0.1 |  | 0.1 |  | (0.6) |
Effective income tax (benefit) rate | 11.4 | % | 5.6 | % | 17.7 | % | 16.2 | % | 5.1 | % | 25.6 | %
| 2022
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Power | Southern Company Gas
Federal statutory rate | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | %
State income tax, net of federal deduction | 6.2 |  | 4.8 |  | 6.5 |  | 4.4 |  | 1.9 |  | 6.4 |
Employee stock plans' dividend deduction | (0.5) |  | — |  | — |  | — |  | — |  | — |
Non-deductible book depreciation | 0.6 |  | 0.5 |  | 0.6 |  | 0.3 |  | — |  | — |
Flowback of excess deferred income taxes | (6.6) |  | (1.9) |  | (9.6) |  | (7.8) |  | — |  | (2.5) |
AFUDC-Equity | (1.1) |  | (0.8) |  | (1.5) |  | — |  | — |  | — |
Federal PTCs | — |  | — |  | — |  | — |  | (6.6) |  | — |
ITC amortization | (1.3) |  | (0.1) |  | (0.1) |  | — |  | (17.2) |  | (0.1) |
Noncontrolling interests | 0.5 |  | — |  | — |  | — |  | 8.4 |  | — |
Other | — |  | 0.3 |  | — |  | 0.3 |  | (0.1) |  | (0.9) |
Effective income tax (benefit) rate | 18.8 | % | 23.8 | % | 16.9 | % | 18.2 | % | 7.4 | % | 23.9 | %
| 2021
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Power | Southern Company Gas
Federal statutory rate | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | % | 21.0 | %
State income tax, net of federal deduction | 5.5 |  | 4.6 |  | (5.7) |  | 4.9 |  | (8.0) |  | 15.1 |
Employee stock plans' dividend deduction | (0.9) |  | — |  | — |  | — |  | — |  | — |
Non-deductible book depreciation | 0.9 |  | 0.5 |  | 3.1 |  | 0.4 |  | — |  | — |
Flowback of excess deferred income taxes | (11.7) |  | (2.6) |  | (49.9) |  | (15.2) |  | — |  | (2.8) |
AFUDC-Equity | (1.5) |  | (0.7) |  | (6.4) |  | — |  | — |  | — |
Federal PTCs | — |  | — |  | — |  | — |  | (4.6) |  | — |
ITC amortization | (2.2) |  | (0.1) |  | (0.4) |  | — |  | (29.7) |  | (0.1) |
Noncontrolling interests | 0.8 |  | — |  | — |  | — |  | 13.4 |  | — |
Leveraged lease impairments and dispositions | (1.4) |  | — |  | — |  | — |  | — |  | — |
Other | (0.1) |  | 0.2 |  | (1.9) |  | 0.6 |  | (0.4) |  | 0.6 |
Effective income tax (benefit) rate | 10.4 | % | 22.9 | % | (40.2) | % | 11.7 | % | (8.3) | % | 33.8 | %
Tax effects between the carrying amounts of assets and liabilities | The tax effects of temporary differences between the carrying amounts of assets and liabilities in the financial statements of the Registrants and their respective tax bases, which give rise to deferred tax assets and liabilities, are as follows:
| December 31, 2023
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Power | Southern Company Gas
| (in millions)
Deferred tax liabilities — |  |  |  |  |  |
Accelerated depreciation | $ | 9,683 |  | $ | 2,566 |  | $ | 3,628 |  | $ | 339 |  | $ | 1,346 |  | $ | 1,576 |
Property basis differences | 2,647 |  | 1,444 |  | 812 |  | 188 |  | — |  | 189 |
Employee benefit obligations | 979 |  | 321 |  | 446 |  | 49 |  | 12 |  | 74 |
AROs | 833 |  | 476 |  | 314 |  | — |  | — |  | — |
Under recovered fuel and natural gas costs | 601 |  | 80 |  | 508 |  | 13 |  | — |  | — |
Regulatory assets – |  |  |  |  |  |
AROs | 1,902 |  | 667 |  | 1,196 |  | 39 |  | — |  | — |
Employee benefit obligations | 797 |  | 213 |  | 260 |  | 37 |  | — |  | 11 |
Remaining book value of retired assets | 369 |  | 143 |  | 221 |  | 5 |  | — |  | — |
Premium on reacquired debt | 63 |  | 9 |  | 53 |  | 1 |  | — |  | — |
Other | 700 |  | 182 |  | 223 |  | 43 |  | 2 |  | 191 |
Total deferred income tax liabilities | 18,574 |  | 6,101 |  | 7,661 |  | 714 |  | 1,360 |  | 2,041 |
Deferred tax assets — |  |  |  |  |  |
AROs | 2,735 |  | 1,143 |  | 1,510 |  | 39 |  | — |  | — |
ITC and PTC carryforwards | 1,387 |  | 12 |  | 691 |  | — |  | 481 |  | — |
Employee benefit obligations | 985 |  | 224 |  | 316 |  | 52 |  | 10 |  | 89 |
Estimated loss on plants under construction | 857 |  | — |  | 857 |  | — |  | — |  | — |
Estimated loss on regulatory disallowance | 26 |  | — |  | — |  | — |  | — |  | 26 |
Other state deferred tax attributes | 363 |  | — |  | 13 |  | 231 |  | 49 |  | 8 |
Federal effect of net state deferred tax liabilities | 418 |  | 215 |  | 92 |  | — |  | 27 |  | 101 |
Other property basis differences | 197 |  | — |  | 83 |  | — |  | 97 |  | — |
State effect of federal deferred taxes | 115 |  | 115 |  | — |  | — |  | — |  | — |
Other partnership basis differences | 85 |  | — |  | — |  | — |  | 85 |  | — |
Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) | 34 |  | 30 |  | — |  | 3 |  | — |  | — |
Long-term debt fair value adjustment | 79 |  | — |  | — |  | — |  | — |  | 79 |
Other comprehensive losses | 67 |  | 4 |  | 4 |  | — |  | 6 |  | — |
Other | 538 |  | 188 |  | 152 |  | 57 |  | 18 |  | 74 |
Total deferred income tax assets | 7,886 |  | 1,931 |  | 3,718 |  | 382 |  | 773 |  | 377 |
Valuation allowance | (206) |  | — |  | (75) |  | (41) |  | (27) |  | (7) |
Net deferred income tax assets | 7,680 |  | 1,931 |  | 3,643 |  | 341 |  | 746 |  | 370 |
Net deferred income taxes (assets)/liabilities | $ | 10,894 |  | $ | 4,170 |  | $ | 4,018 |  | $ | 373 |  | $ | 614 |  | $ | 1,671 |
Recognized in the balance sheets: |  |  |  |  |  |
Accumulated deferred income taxes – assets | $ | (96) |  | $ | — |  | $ | — |  | $ | (96) |  | $ | — |  | $ | — |
Accumulated deferred income taxes – liabilities | $ | 10,990 |  | $ | 4,170 |  | $ | 4,018 |  | $ | 469 |  | $ | 614 |  | $ | 1,671 |
| December 31, 2022
| Southern Company | Alabama Power | Georgia Power | Mississippi Power | Southern Power | Southern Company Gas
| (in millions)
Deferred tax liabilities — |  |  |  |  |  |
Accelerated depreciation | $ | 9,443 |  | $ | 2,564 |  | $ | 3,447 |  | $ | 338 |  | $ | 1,351 |  | $ | 1,505 |
Property basis differences | 2,350 |  | 1,303 |  | 693 |  | 179 |  | — |  | 150 |
Employee benefit obligations | 888 |  | 284 |  | 412 |  | 43 |  | 11 |  | 68 |
AROs | 876 |  | 499 |  | 324 |  | — |  | — |  | — |
Under recovered fuel and natural gas costs | 805 |  | 185 |  | 548 |  | 40 |  | — |  | 32 |
Regulatory assets – |  |  |  |  |  |
AROs | 2,006 |  | 679 |  | 1,285 |  | 42 |  | — |  | — |
Employee benefit obligations | 677 |  | 180 |  | 226 |  | 30 |  | — |  | 15 |
Remaining book value of retired assets | 400 |  | 142 |  | 253 |  | 5 |  | — |  | — |
Premium on reacquired debt | 66 |  | 9 |  | 57 |  | — |  | — |  | — |
Other | 555 |  | 179 |  | 181 |  | 40 |  | 14 |  | 82 |
Total deferred income tax liabilities | 18,066 |  | 6,024 |  | 7,426 |  | 717 |  | 1,376 |  | 1,852 |
Deferred tax assets — |  |  |  |  |  |
AROs | 2,882 |  | 1,178 |  | 1,609 |  | 42 |  | — |  | — |
ITC and PTC carryforwards | 1,685 |  | 12 |  | 673 |  | — |  | 794 |  | — |
Employee benefit obligations | 890 |  | 198 |  | 304 |  | 47 |  | 9 |  | 89 |
Estimated loss on plants under construction | 888 |  | — |  | 888 |  | — |  | — |  | — |
Other state deferred tax attributes | 388 |  | — |  | 12 |  | 239 |  | 51 |  | 7 |
Federal effect of net state deferred tax liabilities | 365 |  | 175 |  | 88 |  | — |  | 28 |  | 92 |
Other property basis differences | 207 |  | — |  | 79 |  | — |  | 109 |  | — |
State effect of federal deferred taxes | 136 |  | 136 |  | — |  | — |  | — |  | — |
Other partnership basis differences | 111 |  | — |  | — |  | — |  | 111 |  | — |
Regulatory liability associated with the Tax Reform Legislation (not subject to normalization) | 137 |  | 127 |  | — |  | 9 |  | — |  | — |
Long-term debt fair value adjustment | 85 |  | — |  | — |  | — |  | — |  | 85 |
Other comprehensive losses | 72 |  | 4 |  | 5 |  | — |  | 5 |  | — |
Other | 552 |  | 213 |  | 186 |  | 62 |  | 17 |  | 28 |
Total deferred income tax assets | 8,398 |  | 2,043 |  | 3,844 |  | 399 |  | 1,124 |  | 301 |
Valuation allowance | (257) |  | — |  | (125) |  | (41) |  | (27) |  | (9) |
Net deferred income tax assets | 8,141 |  | 2,043 |  | 3,719 |  | 358 |  | 1,097 |  | 292 |
Net deferred income taxes (assets)/liabilities | $ | 9,925 |  | $ | 3,981 |  | $ | 3,707 |  | $ | 359 |  | $ | 279 |  | $ | 1,560 |
Recognized in the balance sheets: |  |  |  |  |  |
Accumulated deferred income taxes – assets | $ | (111) |  | $ | — |  | $ | — |  | $ | (107) |  | $ | — |  | $ | — |
Accumulated deferred income taxes – liabilities | $ | 10,036 |  | $ | 3,981 |  | $ | 3,707 |  | $ | 466 |  | $ | 279 |  | $ | 1,560 |
Summary of tax credit carryforwards | Federal ITC/PTC carryforwards at December 31, 2023 were as follows:
| Southern Company | Alabama Power | Georgia Power | Southern Power
| (in millions)
Federal ITC/PTC carryforwards | $ | 829 |  | $ | 12 |  | $ | 131 |  | $ | 481 |
Tax year in which federal ITC/PTC carryforwards begin expiring | 2031 | 2032 | 2031 | 2035
Year by which federal ITC/PTC carryforwards are expected to be utilized | 2029 | 2028 | 2028 | 2029
Summary of operating loss carryforward | At December 31, 2023, the net state income tax benefit of state and local NOL carryforwards for Southern Company's subsidiaries were as follows:
Company/Jurisdiction | Approximate Net State Income Tax Benefit of NOL Carryforwards | Tax Year NOL Begins Expiring
| (in millions) |
Mississippi Power |  |
Mississippi | $ | 183 |  | 2032
Southern Power |  |
Oklahoma | 26 |  | 2035
Florida | 10 |  | 2034
Other states | 2 |  | Various
Southern Power Total | $ | 38 |  |
Other(*) |  |
New York | 11 |  | 2036
New York City | 14 |  | 2036
Other states | 30 |  | Various
Southern Company Total | $ | 276 |  |
(*)Represents other non-registrant Southern Company subsidiaries. Alabama Power, Georgia Power, and Southern Company Gas did not have material state or local NOL carryforwards at December 31, 2023.
Changes in unrecognized tax benefits | Changes in unrecognized tax benefits for the periods presented were as follows:
| Southern Company | Georgia Power | Southern Company Gas
| (in millions)
Unrecognized tax benefits at December 31, 2020 | $ | 44 |  | $ | — |  | $ | — |
Tax positions changes – |  |  |
Increase from prior periods | 3 |  | — |  | — |
Unrecognized tax benefits at December 31, 2021 | 47 |  | — |  | — |
Tax positions changes – |  |  |
Increase from prior periods | 33 |  | — |  | 32 |
Unrecognized tax benefits at December 31, 2022 | 80 |  | — |  | 32 |
Tax positions changes – |  |  |
Increase from prior periods | 88 |  | 86 |  | 2 |
Statute of limitations expiration | (52) |  | (9) |  | — |
Unrecognized tax benefits at December 31, 2023 | $ | 116 |  | $ | 77 |  | $ | 34 |

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