(1) Where a group of corporate bodies opts to be registered as a single unit under subsection (3) of section 12 of the Act, all the members of the group shall adopt the same tax period and the same accounting basis for the tax.

(2) Despite the fact that no output tax shall be paid on transactions between members of the group, each member of the group shall maintain distinct records, including tax invoices, for all transactions between members of the group.