Financial instruments: valuation - Movement in Level 3 portfolios - Liabilities (Details) - GBP (£) £ in Millions	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022
Movement in level 3 liabilities
Financial liabilities at beginning of period	£ 683,557
Financial liabilities at end of period	667,803
Other operating income and interest income
Movement in level 3 liabilities
Gains Losses Recognised In Profit Or Loss Fair Value measurement Assets and Liabilities	0	£ (20)
Income from trading activities
Movement in level 3 liabilities
Gains Losses Recognised In Profit Or Loss Fair Value measurement Assets and Liabilities	4	(5)
At fair value
Movement in level 3 liabilities
Financial liabilities at beginning of period	149,577
Financial liabilities at end of period	136,053
At fair value \| Level 3
Movement in level 3 liabilities
Amounts recorded in the income statement	(84)	139
Level 3 transfers in	7	31
Level 3 transfers out	(5)	(36)
Purchases/Originations	89	154
Settlements/Other decreases	(27)	(15)
Sales	(54)	(133)
Foreign exchange and other adjustments	(5)	2
Amounts recorded in the income statement in respect of balances held at year end - unrealised	(84)	139
Financial liabilities at beginning of period	976	609
Financial liabilities at end of period	£ 897	£ 751

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: Financial instruments, class [member]; Financial assets; Derivatives [member]]

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The gains (losses) recognised in profit or loss for liabilities measured at fair value that are attributable to the change in unrealised gains or losses relating to those liabilities held at the end of the reporting period. [Refer: At fair value [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The gains (losses) including exchange differences recognised in profit or loss on the fair value measurement of liabilities. [Refer: At fair value [member]]

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The amount of transfers of liabilities into Level 3 of the fair value hierarchy. [Refer: Level 3 of fair value hierarchy [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The amount of transfers of liabilities out of Level 3 of the fair value hierarchy. [Refer: Level 3 of fair value hierarchy [member]]

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