| Mar 31,
2018 | Mar 31,
2019 | Mar 31,
2020 | Mar 31,
2021 | Mar 31,
2022 | Mar 31,
2023 |
|---|
| Profit (loss) from operating activities | 3,493 | 2,870 | 2,780 | 2,895 | 4,371 | 4,879 |
|---|
| Gain on sale of investments | - | - | - | - | 228 | 846 |
|---|
| Other fair value movements | - | - | - | -22 | -65 | 21 |
|---|
| Depreciation, amortisation and impairment | 1,530 | 1,588 | 1,640 | 1,672 | 1,830 | 1,984 |
|---|
| Share-based payments | 16 | 27 | 19 | 27 | 38 | 48 |
|---|
| Changes in working capital | -118 | -40 | -394 | -296 | 223 | -547 |
|---|
| Changes in provisions | -206 | -110 | 198 | -195 | 149 | -155 |
|---|
| Changes in pensions and other post-retirement benefit obligations | -239 | -123 | -117 | -55 | -84 | -46 |
|---|
| Cash generated from operations – continuing operations | 4,702 | 4,464 | 4,914 | 4,618 | 5,788 | 6,432 |
|---|
| Tax paid | -8 | 75 | 199 | 157 | 298 | 89 |
|---|
| Net cash inflow from operating activities – continuing operations | 4,710 | 4,389 | 4,715 | 4,461 | 5,490 | 6,343 |
|---|
| Net cash inflow from operating activities – discontinued operations | -207 | -71 | -97 | - | 782 | 555 |
|---|
| Purchases of intangible assets | 173 | 306 | 317 | 426 | 446 | 567 |
|---|
| Purchases of property, plant and equipment | 3,738 | 3,635 | 4,583 | 4,362 | 5,098 | 6,325 |
|---|
| Disposals of property, plant and equipment | 10 | 38 | 68 | 8 | 26 | 87 |
|---|
| Investments in joint ventures and associates | 129 | 143 | 82 | 81 | 265 | 443 |
|---|
| Dividends received from joint ventures, associates and other investments | - | - | - | - | - | 190 |
|---|
| Acquisition of National Grid Electricity Distribution and Contributions to National Grid Renewables and Emerald Energy Venture LLC | - | - | - | - | - | 19 |
|---|
| UK Gas Transmission | - | - | - | - | - | 4,027 |
|---|
| The Narragansett Electric Company | - | - | - | - | - | 2,968 |
|---|
| Millennium Pipeline Company, LLC | - | - | - | - | - | 497 |
|---|
| Cash flows from losing control of subsidiaries or other businesses, classified as investing activities | -20 | - | - | - | - | - |
|---|
| Disposal of financial and other investments | 134 | 18 | 63 | 66 | 215 | 116 |
|---|
| Acquisition of financial investments | 2 | 89 | 108 | 99 | 197 | 95 |
|---|
| Net movements in short-term financial investments | 5,953 | 822 | 7 | -436 | - | 586 |
|---|
| Interest received | 57 | 68 | 73 | 16 | 40 | 65 |
|---|
| Cash inflows on derivatives | - | - | - | 225 | 17 | - |
|---|
| Cash outflows on derivatives | - | - | - | 81 | 122 | 362 |
|---|
| Insurance claim from loss of property, plant and equipment | - | - | - | - | - | 79 |
|---|
| Net cash flow from/(used in) investing activities – continuing operations | 2,237 | -3,190 | -3,201 | -5,116 | -13,885 | 804 |
|---|
| Net cash flow used in investing activities – discontinued operations | - | 156 | 6 | - | -125 | -564 |
|---|
| Proceeds from issue of treasury shares | 33 | 17 | 16 | 16 | 33 | 16 |
|---|
| Transactions in own shares | - | - | - | - | - | 1 |
|---|
| Proceeds received from loans | 1,941 | 2,932 | 4,218 | 5,645 | 12,347 | 11,908 |
|---|
| Repayment of loans | 2,156 | 1,969 | 3,253 | 1,663 | 1,261 | 15,260 |
|---|
| Payments of lease liabilities | - | - | 121 | 112 | 117 | 155 |
|---|
| Net movements in short-term borrowings | - | - | -424 | -759 | -11 | -511 |
|---|
| Cash inflows on derivatives | - | - | - | 58 | 20 | 190 |
|---|
| Cash outflows on derivatives | - | - | - | 185 | 114 | 118 |
|---|
| Interest paid | 853 | 914 | 957 | 835 | 1,053 | 1,430 |
|---|
| Dividends paid to shareholders | 4,487 | 1,160 | 892 | 1,413 | 922 | 1,607 |
|---|
| Net cash flow (used in)/from financing activities – continuing operations | -7,316 | -1,364 | -1,606 | 750 | 8,919 | -6,966 |
|---|
| Cash flows from (used in) financing activities, discontinued operations | -231 | - | - | - | -1,150 | -207 |
|---|
| Net (decrease)/increase in cash and cash equivalents | - | - | - | - | - | -35 |
|---|
| Reclassification to held for sale | - | - | - | - | - | 9 |
|---|
| Exchange movements | -3 | 3 | 4 | -7 | 5 | 7 |
|---|