1. (a) Each TEX-AN user shall be billed for its respective use of TEX-AN services on a monthly basis. TEX-AN users will be billed for the following:

   1. (1) TEX-AN user's actual minute use;
   2. (2) TEX-AN user's actual circuit use;
   3. (3) TEX-AN user's proportionate use (based on minute or circuit use) of common telecommunications services and/or equipment for said services provided to all or some TEX-AN users;
   4. (4) TEX-AN user's total cost for its exclusive use of any telecommunications equipment;
   5. (5) TEX-AN user's nonrecurring charges for any type of service provided by TSD, if applicable; and
   6. (6) TSD's operation charge of an amount not to exceed 15% of the total of the costs listed in paragraphs (1)-(5) of this subsection.
2. (b) Each TEX-AN user shall make payment in full as billed to the TSD within ten days after receipt of its bill.
3. (c) Any institution of higher education extending TEX-AN service to students is responsible for payment directly to the commission of the total charges billed, regardless of whether it is able to collect the student's contribution of the payment.
4. (d) Inquiries, corrections, changes or modifications by TEX-AN users to its bill must be made in writing to the TSD within 30 days of receipt of its bill. Any adjustments to payment will be made in the subsequent billing period.
5. (e) In order to maintain sufficient amounts in the telecommunications revolving account to make timely payments to the telecommunications service providers, the commission may require any TEX-AN users to make advance payments based on the average of each TEX-AN user's prior three-month billing exclusive of charges described in subsection (a)(5) of this section. Advance payments which are not equal to the actual amount due for the subsequent payment period will be adjusted accordingly.
6. (f) All TEX-AN call detail records are maintained by the commission for a period of four years.

Source Note:The provisions of this §121.5 adopted to be effective November 8, 1994, 19 TexReg 8541.