BofA is not the first to offer the service. The Brinks Co., owners of probably the best-known armored car service in the world, had joined together with several banks–including SunTrust, the first bank to offer the service; National City; and Fifth-Third, considered the national leader with some 500 mini-vaults in operation–to provide mini-vault service many months ago. "We're starting to break down the physical portability constraints," notes Nick Alex, senior vice president for product management and development in SunTrust's treasury and payments solutions business. "First, it was checks that could be scanned and remotely deposited. Now, it's currency and even coin."

The payoff of the new service: fewer armored carrier visits, since cash is picked up only when it hits a pre-set threshold, and lower transportation costs; no more risky night deposit runs to bank branches; and less "shrinkage" as cash moves quickly and securely from the cash register to the secure mini-vault, with less handling by employees, Alex notes. For a bank, it means fewer hard cash deposits to handle physically. The security issue around a dispersed network of on-site mini-vaults is still a subject of debate, although no robberies have been reported to date.

All the banks offering on-site mini-vaults consider the contents of the vault to be bank property. That means that if the vault is taken in a robbery, it's the bank's loss, not Chick-fil-A's, reports Bethann Johnston, senior vice president and global product management executive at BofA. While mini-vault cash is not an earning asset, it does count toward a bank's reserve requirement, she explains.

But BofA has brought a few new twists to the service: The equipment it has chosen will provide cash out as well as cash in, so Chick-fil-A managers can withdraw cash and have the withdrawal go on the bank's books in almost real time. Employees can even use the BofA recycler to make change. The Brinks model–the only one in actual operation–is working only with cash-in traffic at this point, because of the cost of cash-out equipment, reports Jim Poteet, vice president of product development at Brinks.

BofA may also differ over who ultimately owns the vault. Brinks owns the mini-vault hardware and charges customers a bundled fee for the whole service, Poteet says. The vault equipment is available from a number of manufacturers in a variety of configurations at a cost between $18,000 and $30,000. "We're still working with the pricing to make sure the value proposition plays out to benefit everybody," says BofA's Johnston.

The buzz about electronic deposits of hard cash has brought a flood of inquiries, led by big-box retailers, medical facilities, insurers and casinos– and their treasury staffs, reports Brinks' Poteet. With mini-vaults, users can reconcile receipts from cash register drawers with reports that emanate from the mini-vault. Treasury managers can also see in almost real time how much cash is sitting in each location's mini-vault.

While SunTrust was quick to enter a promising new field, it has been moving cautiously. "We're moving slowly and making sure we resolve legal issues about discrepancies," Alex reports. "We're on new ground when we start giving deposit credit for money sitting in machines which aren't checked every day. We have a pretty conservative risk management culture here and didn't want to stumble on unforeseen problems."

Despite the question marks, the service seems to be gaining momentum and is expected to move into the mainstream relatively quickly. "Treasuries have upgraded their ACH platforms, automated much of their wire initiation and either converted eligible checks to ACH transactions or scanned checks for remote deposit," observes Fred Purches, Brinks' senior vice president for strategic solutions. "Treasuries have been able to reengineer all of their payments processing except for hard cash. Now, that is finally coming, too."