v3.26.1
Equity - Schedule of fair value of each share award used the Monte Carlo and Black Scholes pricing model and weighted average assumptions (Details)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Jun. 30, 2026
USD ($)
£ / shares
shares
Jun. 30, 2026
USD ($)
$ / shares
shares
Jun. 30, 2025
USD ($)
£ / shares
shares
Jun. 30, 2025
USD ($)
$ / shares
shares
Jun. 30, 2024
USD ($)
£ / shares
shares
Jun. 30, 2024
USD ($)
$ / shares
shares
Disclosure of reserves within equity [abstract]            
Risk free interest rate 3.80% 3.80% 3.90% 3.90% 4.70% 4.70%
Expected life of the awards 34 months 34 months 33 months 33 months 33 months 33 months
Dividend yield 4.40% 4.40% 3.40% 3.40% 2.60% 2.60%
Weighted average share price (in GBP per share) | £ / shares £ 18.57   £ 24.26   £ 31.18  
Weighted average fair value of awards granted in the year (in USD per share) | $ / shares   $ 12.59   $ 18.14   $ 17.57
Number of awards granted in the year (in shares) | shares 3.6 3.6 3.4 3.4 2.1 2.1
Fair value of all awards granted in the year (in million of dollars) | $ £ 46 $ 46 £ 61 $ 61 £ 36 $ 36