Ratebuster keeps it simple to save you money on international phone calls. With Ratebuster instant Dial, you can make cheap international calls instantly by dialling a Ratebuster Access Number before calling your destination. If youre calling from a mobile then RB-Mobile is perfect for making low cost international calls without the need to buy a second SIM card. Just text to pre-pay for calling credit and youll be calling friends and family around the world for less with RB-Mobile