NEW YORK (TheStreet) -- Mobile banking is struggling to attract new customers, but those already using it are doing so more often, according to a survey from RateWatch.

RateWatch, which is owned by TheStreet, surveyed 711 adults in January to get their views on mobile banking and mobile payments.

While the number of people using mobile banking rose only 2% in the past two years, those using it at least once a week climbed to 45% from 37% during the same period.

According to the survey, 36% of respondents never use mobile banking. Some of the top reasons include security concerns, a lack of features on the mobile app and the small size of the smartphone screen or tablet display. 

Security concerns have long been one of the major hurdles in popularizing the use of smartphones for financial transactions. Banks, meanwhile, are trying to convince consumers that they can trust their mobile services.

Though consumers are still hesitant to bank with mobile devices, banks are moving quickly to adopt the capability. About 82% of financial institutions offer mobile banking, according to a 2014 RateWatch survey of 556 companies.

RateWatch thinks demand for mobile banking will keep growing.

"Every indication is that as long as safety concerns are addressed, consumers will continue to increase their demand for mobile banking and the ability to easily, conveniently make purchases and manage their money," the report says.

As demand increases, it'll become even more crucial for banks to offer mobile services, or risk losing customers to competitors, says Kimberly Myszkewicz, marketing manager for RateWatch and who helped put the survey together.

"The more a person is engaged in the service, the more likely they are to stick with that institution for other services," Myszkewicz said.

Mobile banking has already seen growth in certain features like person-to-person payments, which has increased 22% in the past two years, and account-to-account transfers, which increased 17% in the same period. There has also been a 30% increase in mobile bill payments over the past two years.

When the survey asked consumers which mobile banking features they use now or would be interested in using, most said checking account balances, transferring between their own accounts, paying bills, receiving account alerts, and locating ATMs or branches. Other less-popular features were depositing a check remotely through a mobile app, making loan payments, person-to-person payments, and account-to-account transfers.

The report also asked consumers about their interest in making in-store purchases with their mobile devices. About a third said they were likely to use mobile payments, a third said they were unlikely, and a third said they had no interest in mobile payments. Only 29% had actually tried mobile payments already, and only 11% use them at least once a week. This means that Apple(AAPL) - Get Report, Google(GOOG) - Get Report, and other mobile payments players have a long road ahead of them to convince consumers to try out their services.

On a bright note for PayPal, though, 3.2% of respondents in the RateWatch survey cited it as their primary payment source, as opposed to a credit card, debit card, or other source.

When respondents were asked to name specific mobile payment services that they had used in the past year, 38% said Amazon(AMZN) - Get Report Payment, 25% said PayPal In-Store Payment, 16% said Starbucks(SBUX) - Get Report Mobile Payments, 10% said Apple Pay, 7% said Google Wallet, 8% said Square Wallet, 4% said Venmo (which is owned by PayPal), and 4% said Isis/Softcard (which is now owned by Google).