If one of the applicants is unable to apply in person and is 18 years of age or older, any adult person or the other applicant may apply on their behalf. As per Texas Family Code Section 2.006, the person applying on their behalf must present the following to the county clerk:
Please note that subsection (c) of Section 2.006 states that a clerk may not issue a marriage license when both applicants are absent unless the clerk is presented with affidavits stating that the applicants are active duty military members currently stationed in another country in support of combat or another military operation.
As per Section 2.001 of the Texas Family Code, a marriage license may be obtained from any county clerk's office. Many Texas counties now offer an online application process. For assistance, below are links with marriage license information from the county clerk's offices for some of Texas' most populous counties: