Final answer:
A sublease is when a tenant rents out their apartment to another person, while still being responsible for the original lease agreement with the landlord.
Step-by-step explanation:
Tenant A's interest is called a sublease. A sublease is when the existing tenant (Tenant A) rents out their apartment to another person (Tenant B) while still being responsible for the original lease agreement with the landlord. Tenant A becomes the sublessor, while Tenant B becomes the sublessee.
In this arrangement, Tenant A retains their legal rights and responsibilities as the original tenant, and also assumes the role of landlord to Tenant B. Tenant A's interest in subleasing his apartment to Tenant B is called a "master lease" or "head lease." In this scenario, Tenant A is the master or head tenant who originally leased the apartment from the landlord or property owner. Tenant A then subleases the same apartment to Tenant B, creating a sublandlord-subtenant relationship. The original lease between Tenant A and the landlord is referred to as the master lease.