The Office of the Texas Secretary of State (the Office) is the only state agency authorized to issue certificates to authenticate Texas public records. Please review our instructions to request a universal Apostille for a notarized document.Mail in the form along with your original documents that need the Apostille Seal. We can apostille an authorization letter signed and notarized in all 50 U.S. states, District of Columbia, and the U.S. Federal Government (USA Embassy). Are you looking for an example of a Texas Apostille? We provide Texas Secretary of State, U.S Department of State, and embassy document legalization, apostille, and authentication services in Houston, TX. Our Texas Apostille office is located in Harris County and in the City of Houston. We can apostille documents originating from all 254 Counties in Texas. Our Texas Apostille office is located in Harris County and in the City of Houston. We can apostille documents originating from all 254 Counties in Texas.