Tex. Tax Code § 6.23
(a) The county assessor-collector shall assess and collect taxes on property in the county for the county. He shall also assess and collect taxes on property for another taxing unit if:
(b) The assessor and collector for a taxing unit other than a county shall assess, collect, or assess and collect taxes, as applicable, for the unit. He shall also assess, collect, or assess and collect taxes, as applicable, for another unit if:
Acts 1979, 66th Leg., p. 2227, ch. 841, Sec. 1, eff. Jan. 1, 1982.
Amended by Acts 1981, 67th Leg., 1st C.S., p. 125, ch. 13, Sec. 22, eff. Jan. 1, 1982;
Acts 1983, 68th Leg., p. 4819, ch. 851, Sec. 2, eff. Aug. 29, 1983.