Dividend Declaration

JANUS HENDERSON FUND MANAGEMENT UK LIMITED

HENDERSON HIGH INCOME TRUST PLC

LEGAL ENTITY IDENTIFIER 213800OEXAGFSF7Y6G11

4 July 2024

HENDERSON HIGH INCOME TRUST PLC

PAYMENT OF THIRD INTERIM DIVIDEND

Henderson High Income Trust plc announces that a third interim dividend of 2.675p per ordinary share of 5p, in respect of the year ending 31 December 2024, will be paid on 25 October 2024 to holders registered at the close of business on 13 September 2024. This dividend is to be paid from the Company's revenue account. The Company's shares will go ex-dividend on 12 September 2024.

For further information please contact:

David SmithFund ManagerHenderson High Income Trust plcTelephone: 020 7818 4443

Dan HoweHead of Investment TrustsJanus Henderson InvestorsTelephone: 020 7818 4458

Harriet Hall

Investment Trusts PR Director

Janus Henderson Investors

Telephone: 020 7818 2919