TSEM3451 - Trust income and gains: vulnerable beneficiaries: vulnerable person election - time limits
An election can be made no later than 12 months after 31 January following the tax year in which the effective date falls. So, if the effective date is 1 July 2023 (tax year 2023-24) an election must be made by 31 January 2026 if it is to have effect for 2023-24. The time limit can only be extended by written notice to HMRC, and in limited circumstances. Internal users should refer these requests to Trusts Technical. See TSEM11100.