The reference to 'mainly' dependent ensures that the requirement for economic dependency is not absolute. What is required is that the person or child be dependent 'in the main' or 'as to the greater part', and not merely be 'partly' or 'to some degree' dependent on the injured client.
In practice, for the purposes of the SRCA, 'mainly' dependent is to be taken to mean that the person or child was more dependent on the client for economic support than on anyone else. Investigation needs to be carried out to establish the facts of each individual case.
Note that certain social security payments – family tax benefit Part A (previously family allowance), carer allowance, double orphan pension – must not be taken into account when making this determination (see S4(7) of the SRCA).