Can a UN Special Notice be issued without any prior notice or opportunity to respond?

Yes. UN Security Council sanctions listings occur without prior notification to the designated individual — there is no pre-listing hearing or opportunity to present a defence. The Sanctions Committee operates confidentially, and designations become effective immediately upon publication. This ex parte process has been heavily criticised by human rights bodies, including the European Court of Human Rights in Nada v. Switzerland and Al-Dulimi v. Switzerland, which found insufficient procedural safeguards. These judgments have influenced some national courts to require more rigorous review before implementing UN sanctions domestically, creating potential litigation avenues.