What is the difference between income and accumulation units?
An income unit will distribute any interest or dividend income from the fund to you. An accumulation unit is designed to offer you growth in the fund rather than income, so any income generated will be reinvested within the fund.
Note that both income and accumulation dividends are included on your annual tax certificate as the income 'paid' within an accumulation fund is still taxable. When a dividend is paid on an accumulation unit the book cost of the investment is increased to ensure a corresponding reduction of liability to capital gains tax.