Statement Of Financial Position [Abstract]
| Concept |
As at 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
As at 2022-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2021-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
As at 2020-01-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||||||||
| Assets [abstract] | |||||||||||||||||||||
| Non-current assets [abstract] | |||||||||||||||||||||
| Property, plant and equipment | — | — | — | — | — |
3,078,000,000
GBP
|
— | — | — | — | — |
3,075,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Right-of-use assets | — | — | — | — | — |
1,885,000,000
GBP
|
— | — | — | — | — |
1,845,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Investment property | — | — | — | — | — |
33,000,000
GBP
|
— | — | — | — | — |
20,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Goodwill | — | — | — | — | — |
2,424,000,000
GBP
|
— | — | — | — | — |
2,427,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Intangible assets other than goodwill | — | — | — | — | — |
330,000,000
GBP
|
— | — | — | — | — |
320,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Investments accounted for using equity method | — | — | — | — | — |
17,000,000
GBP
|
— | — | — | — | — |
20,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Deferred tax assets | — | — | — | — | — |
10,000,000
GBP
|
— | — | — | — | — |
15,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Non-current assets | — | — | — | — | — |
8,404,000,000
GBP
|
— | — | — | — | — |
8,312,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||||||||
| Current inventories | — | — | — | — | — |
2,749,000,000
GBP
|
— | — | — | — | — |
2,488,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Trade and other current receivables | — | — | — | — | — |
300,000,000
GBP
|
— | — | — | — | — |
290,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current tax assets, current | — | — | — | — | — |
33,000,000
GBP
|
— | — | — | — | — |
20,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Cash and cash equivalents | — | — | — | — | — |
823,000,000
GBP
|
— | — | — | — | — |
1,142,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current assets | — | — | — | — | — |
3,948,000,000
GBP
|
— | — | — | — | — |
3,957,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Assets | — | — | — | — | — |
12,352,000,000
GBP
|
— | — | — | — | — |
12,269,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||||||||
| Equity [abstract] | |||||||||||||||||||||
| Issued capital | — | — | — | — | — |
325,000,000
GBP
|
— | — | — | — | — |
332,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Retained earnings | — | — | — | — | — |
4,025,000,000
GBP
|
— | — | — | — | — |
3,630,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Share premium | — | — | — | — | — |
2,228,000,000
GBP
|
— | — | — | — | — |
2,228,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Treasury shares | — | — | — | — | — |
46,000,000
GBP
|
— | — | — | — | — |
23,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Other reserves | — | — | — | — | — |
196,000,000
GBP
|
— | — | — | — | — |
361,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Equity |
50,000,000
GBP
|
325,000,000
GBP
|
2,228,000,000
GBP
|
4,025,000,000
GBP
|
46,000,000
GBP
|
6,778,000,000
GBP
|
196,000,000
GBP
|
361,000,000
GBP
|
332,000,000
GBP
|
2,228,000,000
GBP
|
3,630,000,000
GBP
|
6,571,000,000
GBP
|
23,000,000
GBP
|
43,000,000
GBP
|
2,994,000,000
GBP
|
332,000,000
GBP
|
2,228,000,000
GBP
|
228,000,000
GBP
|
43,000,000
GBP
|
23,000,000
GBP
|
5,802,000,000
GBP
|
| Liabilities [abstract] | |||||||||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||||||||
| Non-current provisions | — | — | — | — | — |
10,000,000
GBP
|
— | — | — | — | — |
33,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Deferred tax liabilities | — | — | — | — | — |
276,000,000
GBP
|
— | — | — | — | — |
232,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Non-current liabilities | — | — | — | — | — |
2,458,000,000
GBP
|
— | — | — | — | — |
2,515,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||||||||
| Current provisions [abstract] | |||||||||||||||||||||
| Current provisions | — | — | — | — | — |
23,000,000
GBP
|
— | — | — | — | — |
46,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Trade and other current payables | — | — | — | — | — |
2,674,000,000
GBP
|
— | — | — | — | — |
2,520,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current tax liabilities, current | — | — | — | — | — |
46,000,000
GBP
|
— | — | — | — | — |
70,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current liabilities | — | — | — | — | — |
3,116,000,000
GBP
|
— | — | — | — | — |
3,183,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Liabilities | — | — | — | — | — |
5,574,000,000
GBP
|
— | — | — | — | — |
5,698,000,000
GBP
|
— | — | — | — | — | — | — | — | — |