The host country would have committed to sell ITMOs to its partner countries under a CAT agreement, getting technical, political, and financial support in return. Partner countries want to use these ITMOs towards their NDC commitments. Before a host country can engage in bilateral ITMO transactions beyond CAT partners, it needs to ensure that it will provide ITMOs to these partners as per the CAT agreement. Transfers of ITMOs by the host to third parties agreed after the CAT agreement was in place would have to come from mitigation going beyond the level of the transfers defined in the CAT agreement. Alternatively, the CAT agreement could establish that the host reserves the right to sell a certain percentage of emissions reductions achieved beyond their NDC to other countries.
Partner countries can be part of different bilateral and CAT agreements as long as they commit to purchase the volume of ITMOs provided by their host as specified in the CAT agreement.