Tex. R. Civ. P. 108a

(a) Method. Service of process may be effected on a party in a foreign country if the citation

and petition is served:

(1) as prescribed by the foreign country’s law for service in that country in an action in

its courts of general jurisdiction;

(2) as the foreign authority directs in response to a letter rogatory or letter of request;

(3) as provided by Rule 106(a);

(4) pursuant to the terms and provisions of any applicable international agreement;

(5) by diplomatic or consular officials when authorized by the United States

Department of State; or

(6) by other means not prohibited by international agreement or the foreign country’s

law, as the court orders.

The method for service of process in a foreign country must be reasonably calculated, under

all of the circumstances, to give actual notice of the proceedings to the defendant in time

to answer and defend. A defendant served with process under this rule must appear and

answer in the same manner and time and under the same penalties as if the defendant had

been personally served with citation within this state to the full extent that t he defendant

may be required to appear and answer under the Constitution of the United States or under

any applicable international agreement in an action either in rem or in personam.

(b) Return. Proof of service may be made as prescribed by the foreign country’s law, by court

order, by Rule 107, or by a method provided in any applicable international agreement.