Smartphones are an important window into understanding underbanked customers, the Federal Deposit Insurance Corp. said in a report released Wednesday in conjunction with a meeting of the agency's advisory committee on economic inclusion.

"Great potential exists for [mobile financial services] to improve account sustainability by helping underserved consumers obtain more control over their funds and better manage their bank accounts," the report said.

The FDIC conducted 18 focus groups with underbanked consumers during the summer of 2015. It then sought industry input on its findings.

Based on the focus groups, the FDIC found that mobile banking could help address several perceived weaknesses of traditional banking. Cellphone alerts can, for instance, help customers reduce their fee expenses by helping them track of their finances.

Overall, mobile banking can "improve account sustainability, in particular, by helping underserved consumers successfully manage and maintain bank accounts," the report found.

In earlier research, the FDIC found that more than three-quarters of underbanked households had access to a smartphone in 2015, compared with only 71% among fully banked households.

Mobile banking was also more common among underbanked customers; 35.7% of such households reported having used the technology within a year, versus only 31% of fully banked households.

However, the FDIC also noted that mobile banking has its limits. "Challenges still exist to using [it] as an access point to banking, since many [of the focus group] participants preferred to open bank accounts in person and are hesitant to open accounts using their mobile phones," the study found.

And in fact, less than 43% of completely unbanked households had access to smartphones in 2015, according to the FDIC.