The number of households using mobile bill payments doubled in the last year, according to a survey released Wednesday by the financial technology company Fiserv.

Sixteen million U.S. households paid a bill using an app, text or mobile browser in 2013, up from 8 million in 2012, Fiserv said. Smartphone users drove this increase, as bill payments in that group rose 150%, to 30% of smartphone users.

Those who use smartphones to pay bills say they do so because of the convenience (70%), the ability to pay anytime (55%) and the desire to save time (49%). The main reasons why smartphone users do not pay their bills on a mobile device are a preference for using a computer, security concerns and the difficulty of using a small screen, Fiserv said.

Despite the move toward mobile payments, people overwhelmingly prefer to have several options to pay bills, the survey showed. Eighty-three percent of respondents use two or more channels to pay bills, the survey says, and they used an average of 3.2 bill-payment channels each month. Two-thirds said it is important for companies to offer multiple ways to pay bills.

"While new bill payment channels such as mobile and tablet are coming on strong, traditional channels remain in use, creating a need for billers to support an ever-growing set of billing and payments, channels and payment types," said Jardon Bouska, president of Fiserv's Biller Solutions division.

Overall, the percentage of people who pay bills electronically held steady at 74% from 2012 to 2013, while the percent of people who pay at least one bill a month by check fell to 53% from 61%.

The survey polled 3,004 people age 21 or over who have responsibility for paying bills.