Texas Finance Code - FIN § 347.151. Amendment of Credit Transaction

(a) On a consumer's request, a creditor may:

(b) A creditor may collect a charge that does not exceed the amount computed by applying the credit transaction's interest rate or time price differential applicable on the date of adjustment to the remaining amount of the unpaid balance, computed under Section 347.155, for the period that the amount is extended or deferred.

(c) The creditor and consumer may agree to an unlimited number of extensions.  The period of each extension is the period agreed to by the creditor and consumer.