Assuming we’re discussing a co-applicant—someone whose name is on the lease as a tenant—and not a co-signer, it would generally be their responsibility to find a suitable replacement before they exit the lease. This tenant replacement process should be specified in the lease, ideally in an addendum covering scenarios with multiple leaseholders. When all parties have signed the lease, each of them is responsible for fulfilling the lease terms. If a tenant needs to depart, finding another tenant to assume their responsibilities helps to maintain the lease’s integrity and financial obligations.