Many of you are (reasonably) concerned about the legality of recording your phone calls – you probably ask yourself "Is it legal to record phone calls?" or "Am I allowed to record the call without the other party’s consent?", or "Will I get in trouble if I record phone calls?".
The laws on recording phone conversations in US are different and they depend on the location of both parties of the call.
Generally, it is legal to record any conversation where both parties consent to that, but you probably want to know if you are allowed to record phone calls without the consent of the other party.
US federal law requires only one party to consent to the recording of a phone conversation and majority of the states have adopted this law allowing one to record phone calls without informing the other party that the call is being recorded.
However, you have to be aware that there are states that require all parties to give consent that the call is being recorded. These states are California, Connecticut, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Pennsylvania and Washington.
In all other US states it is legal to record phone calls as long as one party has given consent. In those states you can record calls without getting the other party’s consent. So, it is legal for you to record a call without the other party’s knowledge because you are that one party to the conversation that is aware and consent that the call is being recorded.
But be careful, you are good as long as the other party is in one of the one-party notification states so you need to know in which state the other party of the call resides. You should abide by the other person’s state laws because you are the one who knows call is being recorded. Keep this in mind because if the other party is in the two-party consent state, you will need to get the other party’s consent.
We would recommend you check the rules for individual states before you start recording your phone calls: http://www.rcfp.org/taping/states.html
For information about the laws that apply to countries other than US, check and comply with your local regulations on phone calls recording: Telephone recording laws on Wikipedia.