CG57707 | Unit trusts: accumulation units
From HM Revenue & Customs · Capital Gains Manual
No distributions are made to holders of accumulation units. Instead the net amount that would normally be distributed is automatically reinvested in the fund. No new units are issued but the value of the existing holding of units is increased. The notional distribution is treated as allowable expenditure where it is subject to Income Tax in the hands of the unit holder. This treatment applies to both UK resident and non-UK resident trusts. Indexation allowance is given from the date the unit holder became entitled to the notional distribution.