Reservations in International Investment Agreements are a key technique for balancing flexibility of national authorities with international commitments in the field of investment, especially for developing countries. This paper studies the use of such reservations at two levels. First, it assesses the various means that signatories have at their disposal when attempting to preserve flexibility and regulatory autonomy. Second, it explores the revealed preferences for flexibility emerging from the reservation lists of eight International Investment Agreements employing a negative list approach to scheduling non-conforming measures.