30 Del. C. § 538: Abatements.

(a) The Director is authorized to abate the unpaid portion of the assessment of any tax, interest, penalty, additional amount or addition to the tax, or any liability in respect thereof, which is:

(1) Excessive in amount;

(2) Assessed after the expiration of the period of limitations properly applicable thereto; or

(3) Erroneously or illegally assessed.

(b) The Director is authorized to abate any portion (whether or not theretofore paid) of the assessment of any tax, interest, penalty, additional amount or additions to the tax, or any liability in respect thereof, if the Director determines under uniform rules prescribed by the Director that the administration and collection costs involved would not warrant collection of the amount due.