Statement Of Financial Position [Abstract]
| Concept |
As at 2023-09-30 |
As at 2023-09-30 |
As at 2023-09-30 |
As at 2023-09-30 |
As at 2023-09-30 |
As at 2022-09-30 |
As at 2022-09-30 |
As at 2022-09-30 |
As at 2022-09-30 |
As at 2022-09-30 |
As at 2021-09-30 |
As at 2021-09-30 |
As at 2021-09-30 |
As at 2021-09-30 |
As at 2021-09-30 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of financial position [abstract] | |||||||||||||||
| Assets [abstract] | |||||||||||||||
| Non-current assets [abstract] | |||||||||||||||
| Property, plant and equipment |
104,000,000
GBP
|
— | — | — | — |
152,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Goodwill |
2,245,000,000
GBP
|
— | — | — | — |
2,391,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Trade and other non-current receivables |
138,000,000
GBP
|
— | — | — | — |
128,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Deferred tax assets |
56,000,000
GBP
|
— | — | — | — |
19,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Non-current assets |
2,822,000,000
GBP
|
— | — | — | — |
3,014,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current assets [abstract] | |||||||||||||||
| Trade and other current receivables |
376,000,000
GBP
|
— | — | — | — |
355,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Cash and cash equivalents |
696,000,000
GBP
|
— | — | — | — |
489,000,000
GBP
|
— | — | — | — |
567,000,000
GBP
|
— | — | — | — |
| Current assets |
1,114,000,000
GBP
|
— | — | — | — |
883,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Assets |
3,936,000,000
GBP
|
— | — | — | — |
3,897,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Equity and liabilities [abstract] | |||||||||||||||
| Equity [abstract] | |||||||||||||||
| Issued capital |
12,000,000
GBP
|
— | — | — | — |
12,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Retained earnings |
658,000,000
GBP
|
— | — | — | — |
570,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Share premium |
548,000,000
GBP
|
— | — | — | — |
548,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Other reserves |
189,000,000
GBP
|
— | — | — | — |
267,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Equity |
1,407,000,000
GBP
|
658,000,000
GBP
|
548,000,000
GBP
|
12,000,000
GBP
|
189,000,000
GBP
|
1,397,000,000
GBP
|
12,000,000
GBP
|
570,000,000
GBP
|
267,000,000
GBP
|
548,000,000
GBP
|
1,111,000,000
GBP
|
448,000,000
GBP
|
103,000,000
GBP
|
12,000,000
GBP
|
548,000,000
GBP
|
| Liabilities [abstract] | |||||||||||||||
| Non-current liabilities [abstract] | |||||||||||||||
| Non-current provisions [abstract] | |||||||||||||||
| Non-current provisions |
24,000,000
GBP
|
— | — | — | — |
20,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Trade and other non-current payables |
13,000,000
GBP
|
— | — | — | — |
6,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Deferred tax liabilities |
18,000,000
GBP
|
— | — | — | — |
17,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Non-current liabilities |
1,344,000,000
GBP
|
— | — | — | — |
1,174,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current liabilities [abstract] | |||||||||||||||
| Current provisions [abstract] | |||||||||||||||
| Current provisions |
23,000,000
GBP
|
— | — | — | — |
33,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Trade and other current payables |
378,000,000
GBP
|
— | — | — | — |
368,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Current liabilities |
1,185,000,000
GBP
|
— | — | — | — |
1,326,000,000
GBP
|
— | — | — | — | — | — | — | — | — |
| Liabilities |
2,529,000,000
GBP
|
— | — | — | — |
2,500,000,000
GBP
|
— | — | — | — | — | — | — | — | — |