Artikel 12

1. If the requested customs authority considers that the assistance sought would infringe upon the public order, the sovereignty, the security or other essential interests of the requested State, or would involve violation of an industrial, commercial or professional secret in that State, it may refuse to provide such assistance, provide it partly or provide it subject to certain conditions or requirements.
2. If a request for assistance cannot be complied with, the customs authority of the State which has asked for assistance shall be notified without delay and shall be informed of the reasons for the refusal to provide assistance.
3. The obligation to provide assistance shall not cover the provision of information or documents obtained by the customs authorities under powers exercised by them at the request of the judicial authority. However where assistance is requested, such information or documents shall be provided in all cases where the judicial authority, which must be consulted to that effect, gives its consent.
4. If the customs authority of one State requests assistance which it itself would be unable to give if requested to do so by the customs authority of the other State, it shall draw attention to that fact in its request. Compliance with such a request shall be within the discretion of the requested customs authority.