Bank of America has crossed the milestone of 1 million unique active mobile banking customers in a year since it allowed them to bank on the go.

The bank already has 25 million consumers using its online services. Now, these customers and those who bank at the branch can check balances, pay bills, view posted and pending transactions, find branches and ATMs and transfer funds through Bank of America mobile application.

"We see over 100,000 users daily on peak high-usage days," said Lance Drummond, ecommerce and ATM executive for Bank of America, in a statement from the Charlotte, NC, headquarters.

The record was set one month after Bank of America inaugurated the next phase of its "Bank of Opportunity" advertising campaign which pushes mobile as one of the options available to consumers (see story).

The campaign includes a series of new television commercials that promote the bank's savings products in a time of economic uncertainty. BBDO New York handles the account.

Usage of the Bank of America mobile service skews heavily in metropolitan areas. The top 10 cities for Bank of America's mobile banking service are, in descending order, Los Angeles, Atlanta, Washington, Dallas, New York, Houston, Phoenix, Boston, Miami and Anaheim, CA.

The bank claims that the frequency of use by active users increases each month, with more than 4 million mobile banking customer sessions in May.

An analysis of the usage patterns shows that almost all customers use the mobile banking service to see account balances and eight in 10 to review transactions. Four in 10 use their mobile phones to move money or pay bills.

Two-thirds of the mobile banking users are customers under 35 and four out of five are under 45, thus proving that Generations X and Y are embracing mobile banking as much as they have the mobile Web.

Customers access the Bank of America mobile banking service by visiting http://www.bofa.mobi on the phone's browser. They enter their online banking ID and pass code to access the accounts.

The Apple iPhone, Research In Motion's BlackBerry and devices with Microsoft Corp.'s Windows Mobile operating system are the most favored by the bank's mobile customers.

Bank of America said it uses the SiteKey security service and offers the Zero Liability Online Banking Guarantee to ensure that its mobile banking transactions are safe and secure.