Mobile billing is a term used to describe any payment done via a smartphone or any other mobile device, using services that follow strict financial regulations. There are a large number of different types of mobile payments, the most common being the direct mobile billing method. This is a payment method that allows billing the merchandise by charging the buyer to their mobile phone account. What this implies is that the user needs to have a valid deal with a mobile carrier in order to be able to make such a purchase. Direct mobile billing is done in just a few easy steps, which is one of the main reasons why its so popular.