(Undated) -- Three major cell phone carriers are hoping to keep money in the pockets of their customers. AT&T, Sprint and T-Mobile are all putting an end to a practice known as "cramming."

It authorizes third-party vendors to hit customers with outside charges for possibly unknowingly signing up for their service. Vermont Attorney General William Sorrell says it's cost mobile and landline customers as much as two-billion-dollars a year in unwanted charges.

The changes were announced yesterday. It's part of an effort by 45 states to put an end to the practice. Charitable donations, such as texting the Red Cross to help in natural disasters are expected to continue.