25 Del. C. § 5125: Surrender of rental unit keys.

(a) If a lease requires the surrender of rental unit keys as a condition for return of a security deposit, the lease must provide a clear procedure for the surrender and may not require surrender prior to the end of the lease term.

(b) If the last day of the lease falls on a Saturday, Sunday, legal holiday, or other day on which the leasing management office is closed, possession of the rental unit shall be considered to have been returned on the date either of the following occurs:

(1) Tenant surrenders keys to the rental unit in accordance with the procedures set forth in the lease.

(2) Tenant completes the procedure under subsection (d) of this section.

(c) If there is more than 1 tenant on the lease, possession is considered to have been returned to the landlord only when all tenants on the lease have complied with the key surrender procedure set forth in the lease, or as provided in subsection (d) of this section.

(d) If the lease does not provide a clear procedure for the surrender of keys, and the landlord has not provided written instructions for surrender of keys prior to the end of the lease, a tenant may surrender the keys through any of the following methods:

(1) If the last day of the lease term falls on a Saturday, Sunday, legal holiday, or other day on which the leasing management office is closed, the tenant may surrender the keys to the landlord in person on the next business day following the expiration of the lease term.

(2) A tenant may leave the keys in the rental unit or secured drop box identified by the landlord or leasing office, with written notice to the landlord in reference to where the keys are placed and the date of return. If the landlord provides a secure drop box under this paragraph, the landlord must clearly label the drop box as secured and the tenant’s duty to surrender the keys is completed once the keys are deposited in the secured drop box.