Wichita ? As colorful new $20 bills circulate around the nation, more consumers are finding out that the notes do not work on automated payment machines like those found in self-service checkout counters at grocery stores.

The first calls started coming into the U.S. Treasury Department’s Bureau of Engraving and Printing two days ago, frustrating government officials who had worked to overcome the vending machine problems that followed the 1998 redesign of the bill.

This time the problem seems to plague mostly automated payment machines — a relatively recent arrival in the industry, the bureau said.

“We learned from our lack of outreach last time, and we really made an effort to reach out to thousands of business industries and associations so they can start working with their customers and members,” said Dawn Haley, spokeswoman for the Bureau of Engraving and Printing.

When the colorful $20 bill was officially introduced into circulation Oct. 9, the first purchase made with it was stamps from a vending machine at a Washington, D.C., post office.

The ceremonial purchase was no accident.

“The postal service wasn’t ready last time too — so we worked really hard with them,” Haley said. “We definitely wanted to showcase the fact the U.S. Postal Service was ready.”

After the problems following the 1998 redesign, the Bureau of Engraving and Printing wanted to make sure its latest version was technology friendly.

So more than a year before the new bills were put into circulation, the bureau reached out to the vending machine industry, transit authorities and the gambling industry to help them get ready for the new bills, Haley said.

Vending machine manufacturers received test decks of currency to try out on their software and hardware.

But nobody thought about the automated payment machines until the first calls started coming in to the bureau after the new currency was put into circulation.

“The self-service group is really new,” Haley said.

A sign on the automated checkouts at Dillon grocery stores now advises customers to trade their new $20 bills for older bills before using the machines. A similar sign is posted at payment machines at the 600 Sprint stores nationwide.

“This is a minor inconvenience for our customers right now,” said Dan Wilinsky, a spokesman for Sprint.

The company expects to upgrade its machines to accept the bills within a month, he said.

“The cost is nominal to us to put the fix in on this,” Wilinsky said.

Wilinsky declined to specify the cost, but manufacturers of various vending and money changing machines are advertising software and hardware upgrades on the Internet that range in cost from free to $40 per machine.

The new $20 bill is the same size as the previous one and still features the image of Andrew Jackson, the seventh president, on the front and the White House on the back. Along with the traditional green and black colors, the new notes also include faint touches of peach and blue.

Besides color, the new notes include new features aimed at making the bills harder to fake. Some old anticounterfeiting features, such as watermarks, that were included in the bill’s last redesign were kept.

The bureau expects to print 2.7 billion of the new twenties the first year.