21 Del. C. § 402

(a) Except as otherwise provided by reciprocity agreement or other arrangement entered into by the Secretary or by a declaration issued by the Secretary, no motor vehicle or trailer or semitrailer registered in another jurisdiction which requires the payment of a registration fee or fees or taxes of any other nature from an owner of a similar vehicle properly registered in this State for the operation of such vehicle on the highways of such other State shall be operated on the highways of this State unless a fee is paid to the Department, equal in amount to the fee or tax collected by the authorized official or public agency of such other jurisdiction for the operation on its highways of the motor vehicle, trailer or semitrailer properly registered in this State. In the event that the fee or tax collected by such other jurisdiction is imposed for the registration of the vehicle therein, then in no case shall the fee paid to the Department be less than the amount now or hereafter provided for by the laws of this State for the registration of a similar vehicle.

(b) The Secretary shall from time to time promulgate such regulations as may be necessary for the effective enforcement of this section.