v3.24.1.1.u2
Other equity reserves (Details) - GBP (£)
£ in Millions
 12 Months Ended
Mar. 31, 2024
Mar. 31, 2023
Mar. 31, 2022
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance £ (3,860) £ (4,563) £ (5,094)
Exchange adjustments (335) 882 629
Exchange differences reclassified to the consolidated income statement on disposal 0 (170) 0
Net (losses) gains taken to equity 87 105 (180)
Share of net gains of associates taken to equity   1 1
Transferred to profit or loss 213 (136) 39
Net (losses) gains in respect of cash flow hedging of capital expenditure (37) 10 (1)
Tax (60) 6 35
Cash flow hedges transferred to the statement of financial position, net of tax 2 5 8
Other equity reserves, ending balance (3,990) (3,860) (4,563)
Retranslation of net assets offset by net investment hedge (397) 1,080 754
Net gains (losses) in respect of net investment hedges (62) 198 125
Gain on disposal of equity instruments measured at FVOCI     12
Retained earnings      
Disclosure of reserves within equity [line items]      
Gain on disposal of equity instruments measured at FVOCI     82
Translation      
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance 1,306 594 (35)
Exchange adjustments (335) 882 629
Exchange differences reclassified to the consolidated income statement on disposal   (170)  
Other equity reserves, ending balance 971 1,306 594
Cash flow hedge      
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance (61) (85) (48)
Net (losses) gains taken to equity 16 142 (96)
Share of net gains of associates taken to equity   1 1
Transferred to profit or loss 224 (136) 40
Net (losses) gains in respect of cash flow hedging of capital expenditure (37) 10 (1)
Tax (50) 2 11
Cash flow hedges transferred to the statement of financial position, net of tax 2 5 8
Other equity reserves, ending balance 94 (61) (85)
Cost of hedging      
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance (38) (29) (28)
Net (losses) gains taken to equity 37 (12) (2)
Transferred to profit or loss (11)   (1)
Tax (6) 3 2
Other equity reserves, ending balance (18) (38) (29)
FVOCI equity      
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance 0 0 51
Net (losses) gains taken to equity     (70)
Tax     19
Other equity reserves, ending balance 0 0 0
FVOCI debt      
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance 79 103 111
Net (losses) gains taken to equity 34 (25) (11)
Tax (4) 1 3
Other equity reserves, ending balance 109 79 103
Own credit      
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance 0 0 1
Net (losses) gains taken to equity     (1)
Other equity reserves, ending balance 0 0 0
Capital redemption      
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance 19 19 19
Other equity reserves, ending balance 19 19 19
Merger      
Disclosure of reserves within equity [line items]      
Other equity reserves, beginning balance (5,165) (5,165) (5,165)
Other equity reserves, ending balance £ (5,165) £ (5,165) £ (5,165)