v3.26.1
Financial instruments and risk management - Schedule of effectiveness and impacts of hedging relationships (Details) - USD ($)
$ in Millions
 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2024
Disclosure of detailed information about hedges [line items]      
Net financial assets (liabilities) at the beginning of the year $ 24,956    
Net financial assets (liabilities) at the end of the year 23,301 $ 24,956  
Gains/(losses) on net investment hedges 199 (845) $ (70)
Net investment hedges      
Disclosure of detailed information about hedges [line items]      
Increase (decrease) through other comprehensive income, Net investment hedges, Cost Of Hedging (12) 101  
Reclassification Adjustments On Net investment hedges, Before Tax, Cost Of Hedging 9 26  
Fair value hedges      
Disclosure of detailed information about hedges [line items]      
Fair value hedge hedged item at beginning end of the year 205 368  
Instruments in fair value hedge relationship at the beginning of the year (5) (8)  
Borrowings in fair value hedge (9) (163)  
Income statement, Instruments in fair value hedge relationship 2 3  
Fair value hedge hedged item at the end of the year 196 205 368
Instruments in fair value hedge relationship at the end of the year (3) (5) (8)
Derivatives | Net investment hedges | Foreign exchange risk      
Disclosure of detailed information about hedges [line items]      
Net financial assets (liabilities) at the beginning of the year (17) 367  
Income statement, net investment hedge 24 44  
Gains/(losses) on net investment hedges (34) 24  
Other Comprehensive Income Recycled to Income statement (9) (26)  
Other movements 6 (426)  
Net financial assets (liabilities) at the end of the year (30) (17) 367
Gains/(losses) on net investment hedges (22) 77  
Derivatives | Cash flow hedges | Foreign currency debt risk      
Disclosure of detailed information about hedges [line items]      
Net financial assets (liabilities) at the beginning of the year 185 (32)  
Derivatives in cash flow hedge (foreign currency debt) (126) 230  
Hedging of foreign currency debt of the group (113) 161  
Other Comprehensive Income Recycled to Income statement 126 (230)  
Other movements 16 56  
Net financial assets (liabilities) at the end of the year 88 185 (32)
Derivatives | Cash flow hedges | Foreign currency exchange risk      
Disclosure of detailed information about hedges [line items]      
Net financial assets (liabilities) at the beginning of the year 103 27  
Derivatives in cash flow hedge (foreign currency risk) 74 54  
Transaction exposure hedging of the group 58 144  
Other Comprehensive Income Recycled to Income statement (78) (68)  
Other movements (74) (54)  
Net financial assets (liabilities) at the end of the year 83 103 27
Derivatives | Cash flow hedges | Commodity price risk      
Disclosure of detailed information about hedges [line items]      
Net financial assets (liabilities) at the beginning of the year (8) (9)  
Derivatives in cash flow hedge (commodity price risk) (8) (19)  
Commodity price risk hedging of the group 21 (20)  
Other Comprehensive Income Recycled to Income statement 8 19  
Other movements 11 21  
Net financial assets (liabilities) at the end of the year 24 (8) (9)
Derivatives | Fair value hedges | Interest rate risk      
Disclosure of detailed information about hedges [line items]      
Net financial assets (liabilities) at the beginning of the year (210) (376)  
Derivatives in fair value hedge (interest rate risk) 11 166  
Net financial assets (liabilities) at the end of the year (199) (210) (376)
Borrowings | Net investment hedges | Foreign exchange risk      
Disclosure of detailed information about hedges [line items]      
Net financial assets (liabilities) at the beginning of the year (9,561) (8,109)  
Income statement, net investment hedge (7)    
Other comprehensive income, before tax, foreign currency borrowings in net investment hedges 221 (768)  
Other Comprehensive Income Recycled to Income statement 7    
Other movements 3,875 (684)  
Net financial assets (liabilities) at the end of the year $ (5,465) $ (9,561) $ (8,109)