Most residential landlords require tenants to pay a security deposit to cover any repairs needed when the tenant moves out, or to cover the tenant’s failure to pay the last month's rent.

Laws vary from state to state, but many states have statutes that provide the maximum amount of security deposit a landlord may require for a residential lease and the costs for which the landlord may use the security deposit (cleaning, repairs, unpaid rent) following termination of the lease.

These laws also provide a specific deadline (often 30-60 days) for the landlord to return the tenant’s security deposit following termination of the lease—after deducting any amount properly withheld, as allowed by law.

In Delaware, residential landlords can require tenants to pay a security deposit, which is regulated under state law. The maximum amount a landlord can charge as a security deposit is equivalent to one month's rent for leases that are one year or longer. For shorter leases, there is no statutory limit. The security deposit can be used to cover the costs of repairs for damage beyond normal wear and tear, cleaning to restore the rental unit to its original condition, and unpaid rent. Delaware law requires landlords to return the security deposit within 20 days after the termination of the lease. If any portion of the deposit is withheld, the landlord must provide the tenant with an itemized list of deductions. If the landlord fails to meet this deadline or wrongfully withholds the deposit, the tenant may be entitled to double the withheld amount. It's important for both landlords and tenants to document the condition of the rental unit at move-in and move-out to support any deductions from the security deposit.