After figures revealed a frightening increase in scams in the first half of this year, small businesses have been warned by Cifas and Action Fraud to be on high alert for fake invoices.

Fake invoice scams targeting businesses have risen, with 749 businesses reporting that they've fallen victim to this type of scam just from January through June 2015. Fraud prevention experts fear the real figure for 2015 is significantly higher since there are more than five million SMEs in the UK and many crimes go unreported.

Fraudsters pretend to be a supplier and contact the business to say that the account details that an invoice needs to be paid have changed. The innocent employee fixes the account details and the organisation later finds that they have been sending money to a fraudster instead of a supplier.

The warning from Cifas and Action Fraud comes in the middle of summer, a time when fraudsters are known to take advantage of experienced staff going on holiday, leaving less experienced replacements in charge who are more likely to fall for the scam.

Smaller businesses are at greatest risk and may discover it to be more difficult to recover from losing large amounts of money as opposed to larger businesses. Police in Surrey advised that they are investigating two claims where businesses appear to have been deceived out of £1 million.