(a) A secondary mortgage loan that includes precomputed interest and that is a regular transaction may provide for additional interest for default if any part of an installment remains unpaid after the 10th day after the date on which the installment is due, including Sundays and holidays.
(b) A secondary mortgage loan contract that uses the scheduled installment earnings method and that is a regular transaction may provide for additional interest for default if any part of an installment remains unpaid after the 10th day after the date on which the installment is due, including Sundays and holidays.
(c) The additional interest for default under this section may not exceed five cents for each $1 of a scheduled installment.
(d) Interest under this section may not be collected more than once on the same installment.
(e) A secondary mortgage loan that includes simple interest may provide for additional interest for default if any part of an installment remains unpaid after the 10th day after the date on which the installment is due, including Sundays and holidays.
Official text of the Texas Finance Code as published by the Texas Legislative Council.