( CNN ) -- Despite online security concerns , the number of Americans who use mobile devices to access financial services is growing fast , according to new data from comScore . In the fourth quarter of 2010 , almost 30 million Americans accessed their bank , credit card or brokerage accounts from a cell phone or tablet , up 54 % from the same quarter a year earlier . Here 's how that growth breaks down for the three primary mobile banking channels ( note that some people use more than one ) : . Smartphone/tablet app : 10.8 million users , 120 % increase . Mobile web browser : 18.6 million users , 58 % increase . SMS text messaging : 8.1 million users , 35 % increase . Nearly half of those surveyed say they primarily access financial services online via a desktop or laptop computer ; but 26 % said they primarily use mobile services for banking . Only 10 % of respondents primarily do their banking in person at a branch , and only 4 % primarily handle their banking via voice calls . New services that help people avoid trips to the bank or ATM may be helping boost the popularity of mobile financial apps . For instance , many major banks now offer smartphone apps that allow you to make a deposit by taking a picture of the front and back of the check . Why do n't more people access mobile financial services ? comScore found some interesting differences between smartphone users and the nearly three-fourths of U.S. mobile users who own feature phones ( simpler phones that are the next step down from smartphones ) . The biggest obstacle to using mobile financial services is simple habit or preference : 53 % of smartphone owners and 45 % of feature phone owners reported , `` I prefer to conduct my transactions online from a fixed device . '' Intriguingly , a quarter of smartphone users reported , `` Accessing my account through my cell phone is too slow . '' Yet only 9 % of feature phone users had the same complaint , even though feature phones typically rely on slower wireless data networks and have browsers that are more limited and harder to navigate . Roughly a third of both groups reported concerns about mobile security -- and there is reason for concern . In October , Banking Info Security reported that even though computer-based internet access to banking probably poses more security risks , most banks now have a decade or more of experience with managing those risks . In contrast , most banks have less experience with mobile services and their attendant risks , and so the risks are amplified by what the banks simply have n't learned yet . Last fall , the Wall Street Journal reported that several banks were rushing to fix security holes in their mobile apps , mostly regarding how the apps were storing data on cell phones . In general , if you are using a mobile financial services app , it 's a good idea not to save your password in the app . Also , it 's more secure to use the app over your wireless carrier 's network , rather than on an open Wi-Fi network . And , of course , remember to lock your phone with a security code or pattern . The opinions expressed in this post are solely those of Amy Gahran .
29.8 million Americans access their financial accounts from a cell phone or tablet , survey finds . A quarter of smartphone users : `` Accessing my account through my cell phone is too slow '' It 's a good idea not to save your password in the app .