Any Party (member State) of CITES may make a unilateral statement that it will not be bound by the provisions of the Convention relating to trade in a particular species listed in the Appendices (or in a part or derivative listed in Appendix III). These statements are called reservations and may be made in accordance with Articles XV, XVI and XXIII of the Convention.

For species included in Appendix I or II, there are restrictions on when a reservation may be entered. They may be entered either when a State becomes a Party to the Convention or within 90 days after the adoption of an amendment to the Appendices. For example, if the Conference of the Parties agrees at a meeting to transfer a species from Appendix II to Appendix I, reservations against the Appendix-I listing have to be entered within 90 days after the end of the meeting. (See Article XV, paragraph 3, and Article XXIII of the Convention.)

For species (or parts and derivatives) included in Appendix III, a State may enter a reservation at the time of becoming a Party or at any time thereafter. (See Article XVI and Article XXIII of the Convention.)

A Party that has entered a reservation may withdraw it at any time. But, while the reservation is in effect, the Party is formally treated as a non-Party with respect to trade in the species (or specimen) concerned.

Although all Parties have the right to enter reservations, they can cause implementation problems. The Conference of the Parties therefore adopted Resolution Conf. 4.25 (Rev. CoP14), which recommends that Parties that have entered reservations with regard to the inclusion of a species in Appendix I should treat the species as if it were in Appendix II and should include records of the trade in these species in their annual reports.