Before you can submit official U.S. documents (issued by the U.S. authorities or notarized by U.S. public notaries) to Latvia's official institutions, they must be authorized with a special Apostille certification. Usually you can obtain the Apostille certification in the Offices of the Secretary of State of the state where the document originally was issued or notarized. The certification is requested in accordance with the Convention Abolishing the Requirement of Legalization for Foreign Public Documents (concluded October 5, 1961) http://hcch.e-vision.nl/index_en.php?act=conventions.text&cid=41 For detailed information on how and where to authorize your U.S. documents with an Apostille, visit USA-Competent Authority (Scroll down to Section III: Officers of the individual States and other subdivisions as indicated:) (Each state has its own requirements. The fees charged by individual U.S. states vary. The average fee for apostilles is approximately $10. Half of the states have the same or higher fees, and half have the same or less.)