What happens to the lease when one roommate leaves
First determine whether the departing person is a co-tenant, subtenant, or occupant. Then read the lease language on early departure, replacements, assignment, and notice. A lease may continue with the remaining tenants, require a new approved tenant, or require all signers to end it together.
Do not assume the security deposit automatically follows the person leaving. The household may need a private settlement while the landlord retains the original deposit until the tenancy ends.
Put the handoff in writing: departure date, keys, rent through date, replacement process, bills, property condition, and deposit arrangement. Seek local advice if the landlord, master tenant, or roommates disagree about the person’s status.