"Seventy-five percent of our deposit growth comes from customers who use our branches," Thasunda Duckett, chief executive of Chase consumer banking said in an interview. "Customers still visit branches, on average, four times a quarter."

JPMorgan said on Tuesday that it will build up to 400 new branches to expand into 15 to 20 markets in several new states. The building is part of an investment plan that includes $15 billion of new lending and nearly $5 billion in spending and is due in part to the reduction in U.S. corporate taxes and a more favorable regulatory environment.

While the New York-based bank did not say which markets it intends to enter, it noted that it does not have branches in Boston, Philadelphia or Washington, D.C.

JPMorgan has found that people who want to open new accounts look to see which banks have convenient branches even though they will do most of their transactions electronically.

Duckett said branches are critical to establishing the bank's presence locally and serve as hubs for mortgage lending, asset management and services to small businesses, such as accepting daily cash deposits.

Across its established markets where it has 5,130 branches in 23 states, the number of locations is slowly decreasing as the bank consolidates and uses more ATMs, Duckett said.

Chief Executive Officer Jamie Dimon said for years that he would like to try to expand into more cities. But Dimon held back because of the need to build capital for higher regulatory requirements and fund upgrades in information technology.

The federal tax cuts are expected to save JPMorgan, the largest U.S. bank by assets, more than $4 billion annually, analysts estimate.

Duckett said the new branch building will be different from that before electronic transactions were popular. Chase will start with higher mix of ATM kiosks in the markets than it has now. And, the bank will also open scaled-down "Everyday Express" offices of ATMs and as few as two employees.

In 2013, to add to its Florida franchise and gain experience entering new cities, JPMorgan opened three branches in Jacksonville. Now it has 20 branches there.

(This version of the story was refiled to add the word "percent" to paragraph two)

(Reporting by David Henry in New York; Editing by Lisa Shumaker)