Del. Code Ann. tit. 5, § 2234
(b) If interest charged pursuant to § 2229 of this title in respect to a loan has been precomputed and taken in advance, then, in the event of prepayment of the entire indebtedness, the licensee shall refund to such borrower the unearned portion of the precomputed interest charge. This refund shall be in an amount not less than the amount which would be refunded if the unearned precomputed interest charge were calculated in accordance with the actuarial method, except that the borrower shall not be entitled to a refund which is less than $5. The unearned portion of the precomputed interest charge is, at the option of the licensee, either:
(c) As used in subsection (b) of this section: