A mother helped her son exchange 40,000 yen after he stole it from a Japanese student boarding at Whanganui Collegiate School.
The 15-year-old entered housing units at the school, stealing wallets containing cards, New Zealand dollars and foreign currency.
The teenager handed the stolen money to his mother, who cannot be named for legal reasons, asking her to exchange it in November.
She appeared in Whanganui District Court on Tuesday where she pleaded guilty to receiving stolen property.
"She had suspicions about where the money had come from," police prosecutor Drew Morrison told the Whanganui District Court.