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 Washington State, residential landlords can require tenants to pay a security deposit, which is regulated under the Residential Landlord-Tenant Act (RCW 59.18). There is no statutory limit on the amount a landlord can charge for a security deposit. However, the landlord must provide the tenant with a written checklist or statement describing the condition of the property at the time of move-in, which the tenant must sign. Upon termination of the lease, the landlord has 21 days to return the security deposit or provide a written statement showing specific reasons for any amount of the deposit retained. This statement must detail the charges for cleaning, repairs, and any unpaid rent. If the landlord fails to comply with these requirements, the tenant may be entitled to the full deposit back, plus damages and attorney's fees.