Federal law dictates that one-party consent is sufficient enough to record a phone call; however, eleven states stipulate that both parties must consent to any recording. We have clearly marked these states in our app, and we'll prompt you twice if we believe you're recording a phone call that connects with an individual sitting in a "two-party" state.
"Two-party" consent laws govern in California, Connecticut, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, New Hampshire, Nevada, Pennsylvania and Washington.
Unless you have the consent of the person you are pranking in those states to record the call (which would ruin the prank, in some ways), you shouldn't send calls to these people.
It's important to note that "two-party" pertains to where the individual is sitting at the time of the call. If someone resides in a single-party state, but is traveling to a two-party state, the laws of the states where the individual is sitting govern the call.