These bills are for taxpayers who filed their returns paying less than the amount due. The billing notice describes the reason for your bill (such as: underpayment, late payment, calculation or math error, or late and underpayment of required estimates). Taxpayers are encouraged to pay these bills electronically on the CT DRS website Taxpayer Service Center (TSC) or by submitting a check along with the bottom portion of the billing notice. Taxpayers who are experiencing short term financial hardship and are unable to pay in full are encouraged to pay as much as they can; and set up a payment plan for the balance. This may be done in many cases through the TSC; in some cases you will be instructed to contact a Revenue Agent to establish a payment schedule.