5.For British Airways flight, miles required for one-class Upgrade from economy (World Traveller) to round-trip Premium Economy Class (World Traveller Plus Class) award, or from Premium Economy Class (World Traveller Plus) to round-trip Business award is 50% of the equivalent round-trip Economy Class (World Traveller Class) award. For flights do not have Premium Economy Class (World Traveller Plus), upgrade from Economy to Business is allowed.