What is the real legal nature of the obligation that arises between the parties involved in a traffic accident when one of them pays the full amount of the joint and several liability? What is the best way to deal with the problem of claims negotiation when it comes to defining transaction policies for insurers? These are some of the questions posed by the author, and their answers can be found in the pages of this work, which is based on the experience acquired during years of practice and consultancy in the insurance market of the Argentine Republic.