What are my rights to sublease two bedrooms in my apartment after two roommates moved out?

When a tenant sublets all or part of his rental to new residents, he becomes those residents’ landlord—technically, he’s a sublandlord to the subtenants. The subtenants pay rent to the tenant/sublandlord, and the tenant/sublandlord has the legal right to terminate their right to live there. Importantly, the landlord has no direct legal relationship with the newcomers; if he wants to get rid of them, he must also evict the tenant. And if the tenant does not pay the rent, the landlord cannot demand it of the subtenants.

Most leases require the landlord’s consent for a sublet, and many landlords will not allow tenants to bring in permanent residents who are subtenants, rather than full-fledged cotenants. Landlords prefer adding new residents to the lease, as cotenants, because it avoids the cumbersome three-way structure of a subtenancy. Once a resident becomes a cotenant, he is directly responsible to the landlord for rent and for abiding by the terms and conditions of the lease.

You've apparently by-passed your landlord by adding residents without his knowledge or approval. If your lease prohibits unauthorized occupants, it probably also makes a violation of this clause grounds for termination.

But all is not necessarily lost. Go to your landlord and ask for a chance to do things right. Be sure your proposed newcomers are financially sound and will meet the landlord’s screening criteria, just like you did when you initially applied. You may try to present them to your landlord as candidates for a subtenancy—but don’t be surprised if the answer is no. 

Tenants in New York have a unique law, called the Roommate Law, which allows them to add roommates. Tenants subject to rent control, in New York City and San Francisco, for example, have additional rights and responsibilities.