A growing number of customers of the nation's fourth-largest bank can deposit checks without visiting an ATM.

Wells Fargo & Company (WFC) said Wednesday it has rolled out mobile remote deposit in 13 states, up from five in June. The bank says it is sticking with plans to offer the service to customers throughout its service area, which encompasses 39 states and the District of Columbia, by the end of this year.

The feature, which lets a customer deposit a check by snapping a picture of it with a smartphone, is available to Wells Fargo customers who install the bank's app on their Apple or Android mobile device.

Roughly 8.7 million of Wells Fargo's 70 million customers access their accounts via smartphone, text or computer, about five years after the company's initial foray into enabling customers to bank online.

Since then, the company and its rivals have brought out a series of services that let customers pay bills, transfer funds and find ATMs and branches.

"What's happening now is the mobile unique era, where we're moving beyond those basics," Brian Pearce, who heads the mobile banking channel in Wells Fargo's Internet services group, told American Banker. "We're taking advantage of the fact the modern smartphone has a really powerful camera that allows customers to make deposits right from their kitchen table."

Pearce says more customers ask for remote deposit than any other mobile service.

The push for remote deposits comes as mobile banking is on the rise. Almost one-third of people who bank online do so through their mobile devices — a population that is expected to more than double by 2017, according to Forrester Research.

Most of the nation's largest banks are racing to offer mobile remote deposit to their customers within the coming year. In July, Bank of America (BAC) introduced several mobile banking products, including mobile direct deposit, which it expects to offer nationwide by the end of this year. JPMorgan Chase (JPM), Citigroup (C), BB&T (BBT) and U.S. Bancorp (USB) all have added the capability as well.

Some banks, including BB&T and U.S. Bancorp, charge a per-check fee for mobile remote deposit. Others, including Wells Fargo and Bank of America, offer the service free of charge.

For its part, Wells Fargo now offers mobile remote deposit to customers in Alabama, Arizona, Arkansas, California, Connecticut, Kansas, Nebraska, Nevada, New York, Oregon, Texas, Virginia and Washington.

Pearce said the company is pleased with the pilot. "The key here is customers are really excited about it," he added.