Auditor's remuneration (Details) - GBP (£) £ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disclosure of products and services [line items]
Audit fees	£ 20	£ 19	£ 17
Total Auditor's remuneration	47	41	38
KPMG
Disclosure of products and services [line items]
Audit fees	41	33	31
All other fees	1	0	1
Tax fees	0	0	0
Subsidiaries
Disclosure of products and services [line items]
Audit fees	18	14	13
Other audit related fees
Disclosure of products and services [line items]
Audit fees	8	7	7
Other audit related fees \| KPMG
Disclosure of products and services [line items]
Audit fees	5	5	3
Other services
Disclosure of products and services [line items]
All other fees	£ 1	£ 1	£ 1

The amount of fees paid or payable to the entity's auditors.

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The amount of fees paid or payable to the entity's auditors for auditing services.

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The amount of fees paid or payable to the entity's auditors for services that the entity does not separately disclose in the same statement or note.

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