Two calls on same day and no message

Frequent caller.  Several times a week.  Sometimes a couple or three times a day, but never leaves a message so no idea what it is about.

See also: 415-229-7564, 415-229-2346

receive 2-3 calls per day, every other day, from this number, with a caller ID of TIPPIT.  Never leaves messages.  but listens to the voice message, then hangs up when ready to record their incoming voice message.