Early Termination Provisions
Leases often have clauses that allow you to terminate the lease period early for certain reasons, such as relocating due to a new job. Read your lease carefully, looking for such a provision. If there is one, you'll have to abide by the rules of the provision. For example, the provision may require that you give your landlord 30 days' notice or forfeit the security deposit you paid when you moved in. There may also be some financial penalties involved in exercising the provision.
If your lease does not have an early termination clause, you can be held responsible for the rent remaining until the lease period is over. However, typically, if your landlord rents the property after you leave but before your lease period is over, he must deduct any rent collected from the new tenant from what you owe him.
There are various situations in which you may be able to end a lease agreement early -- even without exercising an early termination clause -- without incurring any penalties. For instance, you may be able to sublet your apartment for the rest of the lease period so that someone else pays the rent after you leave. Alternately, if rent rates in your area have increased since you first entered into the lease, you may be able to convince your landlord to let you break the lease, since she can likely turn around and re-rent the property for more than you are currently paying each month.
Landlords will often let good tenants break their leases if the tenants can explain why they need to move. Talk to your landlord and explain your situation in earnest. Then, attempt to negotiate for no or few fees and penalties upon your move. For instance, you might ask a landlord to waive a requirement that you pay one month's extra rent in exchange for promising to leave the property in move-in condition, so that he doesn't have to pay a cleaning company or handyman to get the property ready to re-rent.