Panasonic makes both standalone answering machines and answering machines that are integrated with a phone. When messages are left on the Panasonic answering machine, the message indicator will display a number that corresponds to the amount of messages that are recorded. Each answering machine only has so much capacity, so you should try to delete any unnecessary messages. The exact directions for deleting messages vary per Panasonic model but typically there is a button that will delete the message with one tap.
Press the right-facing arrow on the base of the phone system.
Allow the message(s) to begin to play.
Press the "Delete" or "Erase" button after, during or at the beginning of the message. To delete all messages, press the "Delete" button on phone systems with an integrated answering machine twice. Hold the "Erase" button on standalone answering machines until you hear a beep and the message counter displays zero.