Article 152 explicitly defines who is legally responsible for paying the tax. The owner of an individual establishment, the owner of a permanent establishment, and the Omani company itself are primarily liable to pay taxes to the Authority at the designated times. For joint ventures, the Law imposes 'joint liability', meaning all partners are collectively and individually responsible for the entire tax debt of the venture. This ensures that the Tax Authority has clear recourse for collection from the legal entity or the ultimate responsible parties behind non-corporate business structures.