The under-reported income was offset by losses recorded that year, the person said, meaning no additional tax was paid.
SoftBank was told it booked expenses in the wrong period, made calculation errors when converting foreign denominated debt and under-reported income at overseas affiliates, SoftBank said without providing details.
SoftBank's domestic wireless unit, SoftBank Corp , was also told it under-reported income by 3 billion yen (21.64 million pounds) due to booking expenses in the wrong period, a spokesman for the telco said.
It paid additional tax of more than 1 billion yen, the spokesman said.
By Sam Nussey