Amortisation of expenditure for amalgamation or demerger permits phased deduction across successive years for qualifying companies. Section 35DD permits an Indian company that incurs expenditure wholly and exclusively for an amalgamation or demerger to claim deduction by amortising that expenditure as equal amounts across successive previous years beginning with the year in which the amalgamation or demerger takes place, and prohibits claiming that expenditure as a deduction under any other provision of the Act.