Del. Code tit. 30 § 557
When notice and demand for the payment of any assessed amount of tax, interest, penalty, additional amount or addition to the tax imposed under this title or Title 4 is given to a nonresident taxpayer, and the Director determines that it is not practicable to locate property of the taxpayer sufficient in amount to cover the amount assessed, the Director shall send a copy of the certificate provided for in § 554 of this title to the taxpayer at the taxpayer's last known address, together with a notice that such certificate has been filed with the Prothonotary of New Castle County. Thereafter, the Director may authorize the institution of any action or proceeding to collect or enforce such judgment in any place and by any procedure that a civil judgment of a court of record of this State could be collected or enforced. The Director may also, at the Director's discretion, designate agents or retain counsel outside this State, for the purpose of collecting outside this State any assessed amounts due under this title or Title 4 from taxpayers who are not residents of this State. The Director may fix the compensation of such agents and counsel to be paid out of money appropriated or otherwise lawfully available for the payment thereof, and the Director may require of such agents and counsel bonds or other security for the faithful performance of their duties. The Director is authorized to enter into agreements with the tax agencies or departments of other states and the District of Columbia for the collection of taxes from persons found in this State who are delinquent in the payment of taxes imposed by such other states or the District of Columbia, on condition that such other states and the District of Columbia afford similar assistance in the collection of taxes from persons found in their jurisdictions who are delinquent in the payment of taxes imposed under this title or Title 4. The Director is authorized to enter into similar agreements with the Internal Revenue Service with respect to the collection of taxes imposed under this title and Title 4 and the taxes imposed under the internal revenue laws of the United States.
30 Del. C. § 557