Increase in indebtedness / underpayment.  In the event of an increase in indebtedness beyond the amount stated when the instrument was recorded, the holder of the indebtedness shall pay the tax on the amount of the increase.  Such payment is due on the date of the increase, but may be made without penalty if made within sixty (60) days after the increase occurs (time begins on the execution date).  T.C.A. § 67-4-409(b)(8).

If the holder of the indebtedness fails to pay or underpays the "mortgage tax" including any tax increase due to an increase in indebtedness, then the holder of the indebtedness shall be liable for a penalty, in addition to the tax.  The penalty is double the unpaid tax due or two hundred fifty dollars ($250), whichever is greater. T.C.A. § 67-4-409(b)(12).

The register must report all collections monthly to the Commissioner of Revenue on forms prescribed by the Commissioner and remit such collections by the fifteenth (15th) day of the month following the month of collection.  For collecting and reporting these taxes, the register retains as a commission five percent (5%) of the taxes collected, with fifty-two percent (52%) of this amount remitted to the state treasurer and forty-eight (48%) retained by the register and treated as a standard fee of the office. T.C.A. § 67-4-409(d).

Also, registers may charge and collect a fee of one dollar ($1.00) for issuing each tax receipt. This fee is collected along with the other recording or filing fees. T.C.A. § 67-4-409(d).