Amalgamation liability: inter-company supplies during retroactive periods count in turnover and remain liable for tax. Supplies or receipts of goods or services between companies merged by an order effective from an earlier date, occurring between that effective date and the date of the order, are included in each company's turnover and subject to tax; notwithstanding the order, the companies remain treated as distinct for the period up to the order and their registration certificates are cancelled with effect from the date of the order.