Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept |
As at 2023-12-31 |
As at 2023-12-31 |
As at 2022-12-31 |
As at 2022-12-31 |
As at 2021-12-31 |
As at 2020-12-31 |
|---|---|---|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||||||
| Intangible assets and goodwill [abstract] | ||||||
| Intangible assets and goodwill |
203,000,000
GBP
|
— |
91,000,000
GBP
|
— |
83,000,000
GBP
|
— |
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements [abstract] | ||||||
| Investments in subsidiaries, joint ventures and associates reported in separate financial statements |
665,000,000
GBP
|
— |
728,000,000
GBP
|
— |
743,000,000
GBP
|
— |
| Categories of financial assets [abstract] | ||||||
| Financial assets at fair value through profit or loss [abstract] | ||||||
| Financial assets at fair value through profit or loss, mandatorily measured at fair value | — | — | — | — | — | — |
| Financial assets at fair value through profit or loss, classified as held for trading |
100,696,000,000
GBP
|
— |
79,878,000,000
GBP
|
— |
83,706,000,000
GBP
|
— |
| Cash and cash equivalents [abstract] | ||||||
| Cash equivalents [abstract] | ||||||
| Other banking arrangements, classified as cash equivalents |
28,704,000,000
GBP
|
nil
GBP
|
23,182,000,000
GBP
|
208,000,000
GBP
|
17,430,000,000
GBP
|
— |
| Other cash and cash equivalents | — | — | — |
41,000,000
GBP
|
— | — |
| Cash and cash equivalents |
177,037,000,000
GBP
|
— |
189,907,000,000
GBP
|
— |
140,923,000,000
GBP
|
125,304,000,000
GBP
|
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | ||||||
| Non-current assets or disposal groups classified as held for sale |
20,368,000,000
GBP
|
— |
21,214,000,000
GBP
|
— |
9,000,000
GBP
|
— |
| Miscellaneous assets [abstract] | ||||||
| Restricted cash and cash equivalents |
26,554,000,000
GBP
|
— |
23,395,000,000
GBP
|
— |
9,410,000,000
GBP
|
— |
| Derivative financial assets |
174,116,000,000
GBP
|
— |
225,238,000,000
GBP
|
— |
141,221,000,000
GBP
|
— |
| Loans and advances | — | — | — | — | — | — |
| Loans and advances to banks |
14,371,000,000
GBP
|
— |
17,109,000,000
GBP
|
— |
10,784,000,000
GBP
|
— |
| Loans and advances to customers |
75,491,000,000
GBP
|
— |
72,614,000,000
GBP
|
— |
91,177,000,000
GBP
|
— |
| Cash and bank balances at central banks |
110,618,000,000
GBP
|
177,000,000
GBP
|
131,433,000,000
GBP
|
1,562,000,000
GBP
|
108,482,000,000
GBP
|
— |
| Reverse repurchase agreements and cash collateral on securities borrowed |
73,494,000,000
GBP
|
— |
53,949,000,000
GBP
|
— |
54,448,000,000
GBP
|
— |
| Items in course of collection from other banks |
2,114,000,000
GBP
|
— |
2,285,000,000
GBP
|
— |
346,000,000
GBP
|
— |
| Classes of other provisions [abstract] | ||||||
| Other provisions [abstract] | ||||||
| Other provisions |
390,000,000
GBP
|
— |
424,000,000
GBP
|
— |
562,000,000
GBP
|
— |
| Categories of financial liabilities [abstract] | ||||||
| Financial liabilities at fair value through profit or loss [abstract] | ||||||
| Financial liabilities at fair value through profit or loss that meet definition of held for trading |
42,276,000,000
GBP
|
— |
41,265,000,000
GBP
|
— |
46,433,000,000
GBP
|
— |
| Financial liabilities at fair value through profit or loss, designated upon initial recognition or subsequently |
32,545,000,000
GBP
|
— |
27,282,000,000
GBP
|
— |
33,608,000,000
GBP
|
— |
| Miscellaneous liabilities [abstract] | ||||||
| Derivative financial liabilities |
171,474,000,000
GBP
|
— |
218,867,000,000
GBP
|
— |
139,368,000,000
GBP
|
— |
| Deposit liabilities | — | — | — | — | — | — |
| Deposits from banks |
22,943,000,000
GBP
|
— |
20,836,000,000
GBP
|
— |
32,188,000,000
GBP
|
— |
| Deposits from customers [abstract] | ||||||
| Deposits from customers |
222,941,000,000
GBP
|
— |
215,948,000,000
GBP
|
— |
205,241,000,000
GBP
|
— |
| Subordinated liabilities [abstract] | ||||||
| Subordinated liabilities |
14,920,000,000
GBP
|
— |
14,528,000,000
GBP
|
— |
12,488,000,000
GBP
|
— |
| Debt instruments issued |
13,443,000,000
GBP
|
— |
7,268,000,000
GBP
|
— |
9,428,000,000
GBP
|
— |
| Repurchase agreements and cash collateral on securities lent |
53,416,000,000
GBP
|
— |
32,901,000,000
GBP
|
— |
27,259,000,000
GBP
|
— |
| Items in course of transmission to other banks |
2,116,000,000
GBP
|
2,000,000
GBP
|
2,226,000,000
GBP
|
— |
489,000,000
GBP
|
— |
| Issued capital [abstract] | ||||||
| Issued capital |
797,000,000
GBP
|
— |
797,000,000
GBP
|
— |
797,000,000
GBP
|
— |
| Retained earnings [abstract] | ||||||
| Retained earnings |
24,724,000,000
GBP
|
— |
24,368,000,000
GBP
|
— |
24,157,000,000
GBP
|
— |
| Net assets (liabilities) [abstract] | ||||||
| Assets |
702,970,000,000
GBP
|
— |
716,646,000,000
GBP
|
— |
596,027,000,000
GBP
|
— |
| Liabilities |
678,465,000,000
GBP
|
— |
693,413,000,000
GBP
|
— |
572,882,000,000
GBP
|
— |
| Assets less current liabilities [abstract] |