Scammers are calling schools and pretending to be head teachers demanding a transfer of money - according to a new warning sent out across Northamptonshire today.
The National Fraud Intelligence Bureau (NFIB) says it has seen an increase in recent weeks in the volume of fraud reports where schools are the victim.
It says the trend has resulted in "substantial financial losses for several schools that have fallen victim to this type of fraud".
In the incidents reported a school is targeted by a fraudster pretending to be the head teacher or principal.
The fraudster then contacts a member of staff with responsibility for authorising financial transfers and requests for a one-off, often urgent, bank transfer to be made.
The amounts requested have been between £8,000 and £10,000.
An NFIB spokesman said: "All employees should be aware of these procedures and encouraged to challenge requests they think may be suspicious, particularly urgent sounding requests from senior employees."
"Sensitive information you post publicly, or dispose of incorrectly, can be used by fraudsters to perpetrate fraud against you."
If you have been affected by this, or any other type of fraud, report it to Action Fraud by calling 0300 123 2040, or visitingwww.actionfraud.police.uk.