Del. Code tit. 30 § 5214
The Department of Transportation may require a motor carrier to provide a surety company bond, which at no time shall exceed the amount of $20,000, payable to this State and conditioned that the carrier will pay all taxes due and to become due under this chapter from the date of the bond to the date when either the carrier or the bonding company notifies the Department of Transportation that the bond has been cancelled. The surety shall be a corporation authorized to write surety bonds in Delaware. So long as the bond remains in force the Department of Transportation may order refunds to the motor carrier in the amounts appearing to be due on applications duly filed by the motor carrier under § 5204 of this title without first auditing the records of the carrier including the penalties and interest provided in § 5218 of this title, even though the assessment is made after cancellation of the bond, but only for taxes due and payable while the bond was in force and penalties and interest on these taxes.
30 Del. C. § 5214