I'll verify this with a friend in the field later but I believe the answer is yes--you can transition from non-resident to resident after being in the state for 12 months--but you have to establish a domicile by showing a combination of factors.
Here's what UNT says about it (they operate under the same THECB rules I think):http://unt.custhelp.com/app/answers/det ... urposes%3F
A person who has enrolled in an institution of higher education prior to living in the state for 12 months and who has been classified as a nonresident upon first enrollment in an institution of higher education is presumed to be nonresident for the period during which he/she continues as a student.
However, after residing in the state for 12 consecutive months, the student may apply for reclassification as a resident for tuition purposes provided unequivocal proof of establishment of domicile in Texas can be provided as outlined below.
As for what UT considers to be unequivocal proof:https://admissions.utexas.edu/residency
If you are independent for tax purposes, you may gain resident status if you establish domicile in the state. If your parent(s) claim you as a dependent on their federal income tax return, they must establish domicile in the state for you to claim residency.
To establish domicile, you or your parent(s) must meet the following criteria:
Live in Texas for 12 consecutive months; and
Establish and maintain domicile for 12 consecutive months, as evidenced by:
Gainful employment in Texas;
Note: Student jobs do not qualify as gainful employment.
Sole or joint marital ownership of residential real property in Texas by the person seeking to enroll or the dependent’s parent, having established and maintained a domicile at the residence;
Ownership and operation of a business in Texas; or
Marriage for one year to a person who has established domicile in Texas.