https://www.sos.state.tx.us/elections/candidates/guide/2020/lib-green-nom2020.shtml

In order to become a Libertarian Party nominee for a particular office, you must file an application for nomination with the county or state party chair (PDF), as appropriate.  (Section 181.032, Texas Election Code). The application must be filed no later than 6:00p.m. on December 9, 2019. (Section 181.033, Texas Election Code). Candidates for federal office may file a federal application (PDF). NEW LAW: HB 2504 (2019) — HB 2504 requires that the application for nomination must now be accompanied by either a filing fee or a petition in lieu of filing fee (PDF), delivered to the Secretary of State (for a statewide or district office) or to the county judge (for a county or precinct office), in order for the applicant to qualify for nomination. The amount of the filing fee or the number of signatures required for the petition in lieu of a filing fee is the same amount that is required for a candidate seeking nomination by primary election under Sections 172.024 and 172.025. (NOTE: There are no extra requirements for judicial applicants.) The first day a candidate may submit a filing fee or petition in lieu of filing fee to the Secretary of State or County Judge, whichever is applicable, is November 9, 2019. Candidates should contact their party chairs for details on filing candidate applications. Additionally, though the effective date of the HB 2504 is September 1, 2019, candidates may begin collecting petition signatures immediately.

Key dates for your party’s precinct, county and district conventions are located on this website.

See Section 162.015, Texas Election Code for more details about how primary voting or candidacy affects (or does not affect) candidacy in the general election.