Loan impairment provisions (Details) - GBP (£) £ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Loan impairment provisions
Financial Assets	£ 781,992	£ 799,491
ECL provisions	£ 3,806	£ 6,186
Expected Credit Loss, Provision Coverage	1.03%	1.66%
ECL (release)/charge	£ (1,278)	£ 3,131
Amounts written off	876	937
Individual
Loan impairment provisions
Amounts written off	455	191
Collective
Loan impairment provisions
Amounts written off	421	746
Contingent liabilities [member]
Loan impairment provisions
ECL (release)/charge	34,000	28,000
Financial assets (Other)
Loan impairment provisions
Financial Assets	46,145	55,148
ECL (release)/charge	3	12
FVOCI
Loan impairment provisions
Financial Assets	37,266	44,902
ECL provisions	5	6
FVOCI \| Financial assets (Other)
Loan impairment provisions
Financial Assets	37,266	44,902
ECL (release)/charge	2	2
Amortised cost
Loan impairment provisions
Financial Assets	555,132	504,091
Amortised cost \| Financial assets (Other)
Loan impairment provisions
Financial Assets	8,562	9,806
Loans and advances
Loan impairment provisions
Financial Assets	369,827	372,399
Cash at central banks \| Financial assets (Other)
Loan impairment provisions
Financial Assets	176,300	122,800
Debt securities \| Financial assets (Other)
Loan impairment provisions
Financial Assets	44,900	53,800
Business loans
Loan impairment provisions
ECL provisions	3,806	6,186
Stage 1
Loan impairment provisions
ECL provisions	£ 302	£ 519
Expected Credit Loss, Provision Coverage	0.09%	0.18%
ECL (release)/charge	£ (1,377)	£ (89)
Stage 1 \| Loans and advances \| Amortised cost
Loan impairment provisions
Financial Assets	330,824	287,124
Stage 2
Loan impairment provisions
ECL provisions	£ 1,478	£ 3,081
Expected Credit Loss, Provision Coverage	4.35%	3.90%
ECL (release)/charge	£ (187)	£ 2,601
Stage 2 \| Loans and advances \| Amortised cost
Loan impairment provisions
Financial Assets	33,981	78,917
Stage 3
Loan impairment provisions
ECL provisions	£ 2,026	£ 2,586
Expected Credit Loss, Provision Coverage	40.34%	40.67%
ECL (release)/charge	£ 286	£ 619
Stage 3 \| Individual
Loan impairment provisions
ECL provisions	363	831
ECL (release)/charge	20	194
Stage 3 \| Collective
Loan impairment provisions
ECL provisions	1,663	1,755
ECL (release)/charge	266	425
Stage 3 \| Loans and advances \| Amortised cost
Loan impairment provisions
Financial Assets	5,022	6,358
Stage 3 \| Loans and advances \| Amortised cost \| Individual
Loan impairment provisions
Financial Assets	1,215	2,292
Stage 3 \| Loans and advances \| Amortised cost \| Collective
Loan impairment provisions
Financial Assets	£ 3,807	£ 4,066

The amount of an allowance account used to record impairments to financial assets due to credit losses. [Refer: Financial assets]

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The amount of assets that are: (a) cash; (b) an equity instrument of another entity; (c) a contractual right: (i) to receive cash or another financial asset from another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially favourable to the entity; or (d) 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 receive 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 the entity’s own equity instruments do not include puttable financial instruments 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. [Refer: Financial instruments, class [member]; Financial liabilities]

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The amount of impairment loss on financial assets. [Refer: Financial assets; Impairment loss]

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The rate of provision coverage for expected credit losses.

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