However, all is not lost for you. When a tenant breaks a lease, most states require the landlord to take reasonable steps to rerent the unit and credit the new rent toward the remainder on the lease. This is known as mitigating the damages -- and it means that the departed tenant will be liable only for the months the unit was vacant. In a tight housing market, this liability should be no more than a month or so. If there are lots of vacancy signs, however, or if your rent was high, it may be harder for the landlord to rerent -- and you may be on the hook for a greater number of months.

If your landlord stands firm but foolish and takes no steps to rerent and then attempts to collect the balance of the rent in a lawsuit, the judge hearing the case will determine when the unit would have been rented had the landlord acted properly and advertised for a new tenant. You'll end up responsible for the months between your departure and that date only. Again, if the housing market is tight, you will have less to lose.

Since you know that you need to leave town early, you have an advantage over tenants who leave on the spur of the moment. Approach the landlord now and explain that you will need to leave early. The landlord might simply say "Okay" and let you out of the lease. At second best, your landlord may be willing to begin advertising your townhome now, before your intended departure. Be accommodating in allowing prospective tenants in to see the place. If someone is available to move in shortly after you leave, you will not be liable for much, if any, rent.