Financial instruments - classification - Liabilities (Details) - GBP (£) £ in Millions	6 Months Ended
Jun. 30, 2025	Dec. 31, 2024
Financial instruments
Liabilities	£ 688,802	£ 668,607
Financial Liabilities	688,802	668,607
Bank deposits
Financial instruments
Financial Liabilities	38,148	31,452
Items in course of transmission to other banks	404	136
Customer deposits
Financial instruments
Financial Liabilities	436,756	433,490
Settlement balances
Financial instruments
Financial Liabilities	9,546	1,729
Trading liabilities
Financial instruments
Financial Liabilities	58,845	54,714
Derivatives
Financial instruments
Financial Liabilities	65,983	72,082
Net hedging derivative liabilities	460	464
Other financial liabilities
Financial instruments
Financial Liabilities	65,940	61,087
Increase (decrease) in fair value of financial liability, attributable to changes in credit risk of liability	0
Subordinated liabilities
Financial instruments
Financial Liabilities	6,006	6,136
Notes in circulation
Financial instruments
Financial Liabilities	3,287	3,316
Other Financial liabilities
Financial instruments
Financial Liabilities	4,291	4,601
Loans to customers - amortised cost
Financial instruments
Finance lease receivable	9,056	8,998
Held-for-trading
Financial instruments
Financial Liabilities	124,828	126,796
Held-for-trading \| Trading liabilities
Financial instruments
Financial Liabilities	58,845	54,714
Held-for-trading \| Derivatives
Financial instruments
Financial Liabilities	65,983	72,082
DFV
Financial instruments
Financial Liabilities	4,161	3,782
DFV \| Other financial liabilities
Financial instruments
Financial Liabilities	3,927	3,548
DFV \| Subordinated liabilities
Financial instruments
Financial Liabilities	234	234
Amortised cost
Financial instruments
Financial Liabilities	556,148	534,112
Lease liabilities	563	630
Amortised cost \| Bank deposits
Financial instruments
Financial Liabilities	38,148	31,452
Amortised cost \| Customer deposits
Financial instruments
Financial Liabilities	436,756	433,490
Amortised cost \| Settlement balances
Financial instruments
Financial Liabilities	9,546	1,729
Amortised cost \| Other financial liabilities
Financial instruments
Financial Liabilities	62,013	57,539
Amortised cost \| Subordinated liabilities
Financial instruments
Financial Liabilities	5,772	5,902
Amortised cost \| Notes in circulation
Financial instruments
Financial Liabilities	3,287	3,316
Amortised cost \| Other Financial liabilities
Financial instruments
Financial Liabilities	626	684
Other Financial liabilities
Financial instruments
Financial Liabilities	3,665	3,917
Other Financial liabilities \| Other Financial liabilities
Financial instruments
Financial Liabilities	£ 3,665	£ 3,917

The increase (decrease) in the fair value of a financial liability that is attributable to changes in the credit risk of that liability. [Refer: Credit risk [member]]

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- Definition

The amount of derivative financial liabilities held for hedging. [Refer: Derivative financial liabilities]

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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

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No definition available.

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- Definition

The amount of receivables related to finance leases.

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- Definition

The amount of liabilities that are: (a) a contractual obligation: (i) to deliver cash or another financial asset to another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially unfavourable to the entity; or (b) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to deliver a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose, rights, options or warrants to acquire a fixed number of the entity’s own equity instruments for a fixed amount of any currency are equity instruments if the entity offers the rights, options or warrants pro rata to all of its existing owners of the same class of its own non-derivative equity instruments. Also, for those purposes the entity’s own equity instruments do not include puttable financial instruments that are classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. As an exception, an instrument that meets the definition of a financial liability is classified as an equity instrument if it has all the features and meets the conditions in paragraphs 16A-16B or paragraphs 16C-16D of IAS 32. [Refer: Classes of financial instruments [domain]; Financial assets; Derivatives [member]]

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- Definition

The amount of items that have been transmitted to but not yet received and processed by other banks.

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- Definition

The amount of liabilities related to the entity's leases. Lease is a contract, or part of a contract, that conveys the right to use an underlying asset for a period of time in exchange for consideration.

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The amount of a present obligation of the entity to transfer an economic resource as a result of past events. Economic resource is a right that has the potential to produce economic benefits.

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