Based on my experience in 2023/24 and 2024/25.

in 23/24- BAH holiday points posted after the year end, but the points from the holiday were added to the previous year, this was under the old rules of double points, so may have changed. To be clear, these were points doubling the points for each flight under the old rules, so I wanted them to double for each flight separately and be assigned to each year as the date flown, but they all credited to the prior year and I couldn’t get them moved.

in 24/25- The points from the flights themselves posted to their correct year, retrospectively in the case of the first flight. ie flew on 26 March and 3 April. Points for 26 March flight posted in April, but attached themselves to the previous year.