a tax which was abolished in 1999, paid by a company in advance of its main corporation tax payments. It was paid when dividends were paid to shareholders and was deducted from the main tax payment when that fell due. It appeared on the tax voucher attached to a dividend warrant. nouna tax which was abolished in 1999, paid by a company in advance of its main corporation tax payments. It was paid when dividends were paid to shareholders and was deducted from the main tax payment when that fell due. It appeared on the tax voucher attached to a dividend warrant.AbbreviationACT