This note considers the changes to pensions tax allowances announced at the Spring 2023 Budget and charts their implementation through amendments to tax legislation. Interim measures were introduced for the 2023/24 tax year pending further changes that came into effect at the start of the 2024/25 tax year. The key change is the abolition of the lifetime allowance that applied to saving in registered pension schemes from 6 April 2006 until 5 April 2024.