An estimated 39,500 1,000 yen notes supplied by the National Printing Bureau to the Bank of Japan last fall are believed to have printing errors, resulting in some being rejected by vending machines, the bureau said Tuesday.
The bureau attributed its largest printing error ever to flaws in the printing process at one of its plants, but it declined to give specifics for fear of revealing techniques designed to thwart counterfeiters.
According to bureau officials, the flawed notes were printed at the Takinogawa plant in Kita Ward, Tokyo, on Sept. 12 and Oct. 3 and were delivered to the BOJ in January and February.
All the notes are still in circulation, and the BOJ said they can be used at stores and other places as usual. But holders wishing to change them for other notes can do so at the central bank's head and branch offices.
The glitches were reported by a manufacturer of automated teller machines.