Article 43 of the GCC Common VAT Agreement establishes the principle of joint liability. It stipulates that any person who wilfully participates in a violation of the Agreement or the corresponding Local Law will be held jointly liable alongside the person primarily obligated to pay the tax. This shared liability covers the full amount of tax due and any other associated amounts resulting from the violation. The article provides a foundational rule for accomplice liability in tax non-compliance. Furthermore, it explicitly grants each Member State the autonomy to define and implement other specific instances of joint liability beyond those detailed in this provision.