The threshold below which a certificate of origin is waived differs from one trade agreement to another. Therefore, it is important for traders to examine the applicable trade agreement carefully to find out whether or not they will need a certificate of origin for a certain shipment. The provision on exemption or waiver of certificate of origin is often provided unambiguously in the protocol or annex on rules of origin of the relevant agreements. They may also check and compare the exemption thresholds of various trade agreements by using the Rules of Origin Facilitator, a free tool developed by the International Trade Centre - a free tool developed in a joint initiative with the WCO and WTO to assist small and medium-sized enterprises.