Bt 6500 fed up with sales calls interrupting you at home the new bt6500 brings you unique functionality to block nuisance or unwanted calls its call management feature puts you back in control by enabling you to choose the calls you want to take and those you want to block block nuisance calls with the bt 6500 you can choose the type of calls you want to block for example international and withheld numbers can be blocked which account for a large proportion of unwanted sales calls c