Bank of America might be lagging some of its competitors in mobile banking user growth, but the bank is increasing its remote deposit business at an enviable rate.

The bank said yesterday that 13% of its deposits last quarter — or roughly $4.5 billion of a total $34.2 billion of new deposits last quarter, by our calculation — came through RDC. That percentage is 30% higher than in the same quarter a year ago. By comparison, BAC increased its mobile users about 18% during that period.

The increase in RDC volume was enough for Brian Moynihan, Bank of America’s CEO, to point to it yesterday during the BAC earnings call as one reason why the bank’s “expenses were managed tightly” during the quarter. Non-interest expense at Bank of America declined from the fourth quarter of 2014 as a result of the bank reducing the number of its financial centers and “the associated cost driven by consumer behavior patterns shifting to more digital,” he said. The shift in question is the one to RDC for deposit making.

It is worth noting that the Federal Reserve’s recent report on mobile financial services indicated that mobile check deposit was the fourth most commonly used mobile banking feature, with 51% of mobile banking customers reporting that they had made check deposits using mobile phone cameras during 2014. In 2013 just 38% of adults surveyed reported using their mobiles to deposit checks. The Fed numbers imply to us that if Bank of America would remove some of the governors on its RDC program, such as the monthly limit on remote deposits, the bank’s RDC volume would increase further.