When your contract is up can you switch plans with out having a new contract? and if you don't like the new plan can you switch back? I am waiting for cable to come into area is why I ask.
but to answer the end of agreement question. Yes you can switch without a new agreement only a move to a new location (requires new account) or if you were turned off/disconnected to non-pay and have to restart (again a new account) requires a new agreement other transactions (plan changes) don't require a new agreement.