Article 4 establishes the legal framework for Tax Groups. It mandates that the specific terms and conditions for registering, amending, or cancelling a Tax Group will be determined by the Regulations. For tax purposes, all members constituting a Tax Group are to be treated as a single Taxable Person. A critical provision of this article is the imposition of joint and several liability on all members for the Tax obligations of the group. This liability extends to all tax debts and obligations that arise during the period of their membership within the said Tax Group.