Are you speaking to a business or a person?
If a business is called, the phone should be answered with the business's name and (maybe) the answerer's title or name.
If a person (residence) is called, "Hello!" is a courteous invitation for you to identify yourself. It is the CALLER's responsibilty to identify one's self, NOT the recipient's. Remember that a telephone is perhaps the rudest interruption invented. While Caller Identification (Caller I.D.) is available to many, please recognize that you are knocking on my door -- I have the responsibility to recognize you before opening it or conversing with you. (Maybe your time is not valuable, most people value their time and their privacy.)