If you are applying for residency in Costa Rica you will need to have the documents issued in your country of origin legalized so that they are valid for use in Costa Rica.
How do you do this. The first step is to ask if your country is a member of The Hague Convention on the Authentication of Foreign Documents.
What is the Hague Convention ?
The Hague Convention was formed in 1893 with the intent of unifying the rules of private international law. It does so by implementing multilateral agreements and standardizing some of the principles of international law. There are currently 72 countries that are members of the Hague Conference.
How About Costa Rica?
Costa Rica adhered to the “Hague Convention Abolishing the Requirement for Legalization of
Foreign Public Documents” also known as the “Apostille Treaty”. Costa Rica has been a member of the Apostill Treaty since 2011 and as such it will accept foreign documents that have an Apostille attached to it issued by any of the other 72 member countries. The United States and most European countries are members. Canada is not a member. (See the list of member countries below).
Prior to this treaty any foreign document that had to be used in Costa Rica for any legal purpose such as residency or court proceedings had to go through the local country authenticating office and then had to be sent to the Costa Rican Embassy or Consular office in the originating country for further authentication.
With the Apostille Treaty in place the Embassy or Consular Authentication will NOT be required for foreign documents issued by member countries. Instead, once the document has been authenticated (Apostilled) by the originating country authority it can be sent directly to Costa Rica where it will be valid.
If you want to read the full text of the Treaty you can do so below where the full text is available.
The following is a link to the list of the Members of the Hague Convention that have signed the legalization of foreign documents treaty.