How long does a landlord have to refund a security deposit?

A landlord must send the tenant an itemized accounting of the amount retained from the security deposit and/or refund the deposit not retained within 21 days of the date a tenant vacates the unit. That is generally true, but the law now allows the landlord to send an interim accounting within that time if he has good cause for the delay and he has more work to be done and more deposit to account for. Then he needs to send a final accounting within 14 days of completion.