When a tenant vacates prematurely, the landlord can typically withhold the security deposit to cover rent that would be owed to him if it were not for the abandonment by the tenant. However, that may not be the case here. Absent an express agreement, the length of tenancy is measured by how often you collect rent. So for example, where rent is collected on the first of each month, the tenancy would be month to month. A tenant choosing to vacate at the end of a monthly period in that case would not be premature, and so the landlord would not be entitled to withhold the security deposit. We offer landlords a free case assessment. To schedule an assessment online 24/7 by going to go.oncehub.com/rhbooknow or calling us at 303-688-0944. I would recommend you speak with an attorney as soon as possible.