The principle of party autonomy is the guiding principle in international commercial arbitration. When choosing how to resolve their dispute, parties often resort to arbitration due to flexibility and time-efficiency it guarantees. Nevertheless, throughout the arbitration practice it has become clear that the autonomy of the parties is not without limits because each arbitral institution demands to protect the quality of its administration. In particular, when choosing an arbitral institution, the parties agree to comply with the already set arbitration rules, provided by that arbitral institution. In turn, the arbitral institution guarantees certain level of quality of arbitral proceedings, achieved through following the carefully composed arbitration rules. Therefore, there is a contractual obligation imposed upon the arbitral institution to ensure effective administration and quality decision-making. Moreover, there is a contractual obligation imposed upon the parties to act in accordance with the agreed arbitration rules by not deviating from them to the extent where such deviation would hinder the arbitral institution’s contractual obligation. This paper will focus on the analysis of rationale of limiting the principle of party autonomy in general. Furthermore, it will assess four main arbitral institutions’ rules and the mandatory provisions found in each. This paper will, basing its analysis on four main arbitral institutions, demonstrate how the scope of activity of arbitral institution on the one hand, and the autonomy of the parties on the other varies significantly from one set of rules to the other.