Tex. Loc. Gov't Code § 61.007

If a majority of the votes received in each municipality favor consolidation, as soon as practicable after the returns are made, the mayor or chief executive officer in each municipality shall certify to the secretary of state an authenticated copy of the returns under the municipality's seal showing the approval of the consolidation by the voters of the municipality. The secretary of state shall file the authenticated copy and record it in a separate book the secretary of state shall keep for the purpose.