Banks are experimenting with a tool that could shorten your wait times in the teller line or at the ATM: your ­smartphone.

The technology, called ­"pre-staging," would let you start a transaction on your phone and complete it at a teller line or an ATM.

"It's one of the next innovations from a banking ­perspective," said Miranda Hill, the Seattle-based manager for Wells Fargo's digital innovation lab. Earlier this year, the San Francisco-based bank tested the technology in Charlotte and Phoenix.

In theory, pre-staging could shorten transaction times at branches or ATMs. That's because the technology is expected to eliminate steps customers must take today (think using those pneumatic tubes or showing a teller your driver's license).

Besides shortening transaction times, the technology also might make ATM transactions more secure, because ­pre-staging is expected to eliminate the need to swipe debit cards at ATMs. Today, fraudsters can steal debit card data using skimming devices they install on ATMs.

"I would say for the most part we think of this as a choice, another choice, for them (customers) to be able to engage with us, but it's also very convenient," said Hill of Wells Fargo.

Hill said Wells Fargo tested the program with its employees, and is still reviewing feedback. The lender has not made a final decision about whether to offer the technology.

Ed O'Brien, a banking ­analyst for Maynard, Mass.-based Mercator Advisory Group, said there's "quite a bit of testing" within the banking industry of pre-staging technology for ATMs. But he knows of only about a dozen U.S. banks making it available to customers.

It is likely that pre-staging will make transactions faster and more secure, he said. But, he said, the success of pre-staging will also rest in large part on whether it is more convenient than how we currently conduct our banking ­transactions.

"If it's not necessarily easier … then tell me why it's better for me?"