One Number is a feature on a telephone network that allows an incoming call to a called party, which would be redirected to a mobile number or fixed number where the desired party is situated. The fee charging structure for a calling party to place a call to the called party which has their number forwarded can be subtle: if the called party has forwarded their number to a mobile number, the caller could incur higher rates due to the subsequent use of the mobile network. However, Level 1 Communications One Number service offers one flat rate to ease the cost of high bills.