I've never seen a lease with that stipulation and doubt if it is a part of your lease. However if you terminate the lease 4 months prior to its stipulated termination date then you owe the landlord four months rent. You rented the lease for a year, I assume, and that is the deal you made with the landlord and he is expecting a year's worth of rent. Most landlords will allow you to find a replacement tenant and allow you to negotiate something with them. Give him/her a call and see what they think.