If you were to have left USS on 31 August 2025, you would get 5/12 of the rate from the Increases Order 2025, as you would have worked and actively paid in to USS in five months of the 2025-2026 benefit year. This proportionate increase would be applied to the Retirement Income Builder benefits you had built up to and including 31 March 2025 – any benefits built up during your final five months of membership would have only just been earned and would not yet receive any inflation protection.
The same Increases Order would apply whatever date you leave in the year (except 31 March, see below). We always round up any incomplete month to a full month. So, whether you left on 31 August or 1 August, the same rate (based on 5/12 of the rate from the relevant Increases Order) would apply. The increases described in the above examples are subject to the USS increases cap (see below).