Excise bills are generated by the Registry of Motor Vehicles. Bills are mailed to the last known mailing address that the registry has on file. If you move you should contract the Registry of Motor Vehicles and inform them of your new mailing address.
Bills are issued on an annual basis, in January or February of the calendar year.
If a new vehicle is purchased during the calendar year, you will receive another excise tax for that vehicle.
Excise taxes are due 30 days from the date of issue.