I recently researched the provisions of the Hague Convention for service of documents on a client who is a European national. The Hague Service provisions are a handy tool for service of certain types of documents on overseas residents. But, one must take special care/caution. Rules differ for different countries. The text of the treaty is self-explanatory, but countries differ on particular methods of service.
Each contracting country must designate a Central Authority which undertakes requests for service of documents. Some members require translation of the document(s) and specialized service (for example, no service by mail or involuntarily).
From the above description, Belize has rules I am obviously not familiar with. In an abundance of caution, check the Articles applicable to the countries that you are dealing with.