Liability on amalgamation: inter-company supplies treated as taxable turnover when a merger order is retrospective under GST law. When companies are amalgamated by a retrospective order, inter-company supplies and receipts from the retrospective effective date until the order date are included in each company's turnover and liable to tax; notwithstanding the order's effect, the companies are treated as distinct companies for purposes of the Act up to the order date and their registrations may be cancelled with effect from that date, with undefined terms to be read by reference to statutory definitions.