When a tenant leases the unit to someone else. Not all leases grant this permission to the tenant. In many cases the landlord will require notification prior to your subleasing the unit. This does not relieve you of responsibility for the lease - it simply provides someone else to pay the rent.
when the tenant of a leased unit rents it out to someone else. The tenant pays the landlord rent, and the third party rents from the tenant at a higher price, thus giving the original tenant the chance to earn a small profit in the process.
To rent property you lease to another person while still maintaining your responsibility to your landlord under your rental agreement. You are responsible for the actions of your sublessee. This is not the same as assigning, where you transfer the responsibility of your agreement to the new tenant. See assign.
When a tenant in a rental building decides that he/she must rent out their apartment for a short period of time because he/she is leaving New York, he/she has an opportunity to assign his/her lease to another tenant for the period of time that he/she will be out of town. These types of sublets are usually furnished and last for less than a year in duration.
When a tenant sublets, he usually needs to obtain the landlord's prior written consent or licence to do so. A business lease usually contains a term preventing the tenant sub-letting or parting with possession of the property by allowing a third party to occupy all or part of the premises. This absolute prohibition can be subject to subletting being permitted with the landlord's specific consent. For subletting, the landlord's greatest concern will be to ensure that the sub-tenant has no greater security that the tenant himself - for example that he does not obtain the tenant's statutory renewal rights. Since the existing tenant remains directly liable under the lease for rent, the landlord ought not to be particularly concerned over the credit worthiness of the sub-tenant. In any event the landlord will charge the tenant for his legal and other costs in considering and granting a licence