Police in Sunderland are warning shops and businesses to be on the guard to counterfeit money.
On Monday April 18 police received four reports a man had attempted to use a countefeit scottish £20 note at four different premises in Hind Street, near the city centre; Green Terrace, also in the city centre; Millum Terrace in Monkwearmouth; and Harbour View, in Roker.
The man attempted to use the notes between 4.20pm and 8pm.
Officers are urging businesses and traders to be extra vigilant when cash transactions are being made to them.
Detection pens and ultra violet devices should be used when notes are given and any notes which show to be counterfeit should not be accepted.
Further information about spotting counterfeit currency is available at www.bankofengland.co.uk/banknotes.
Anyone with information about the counterfeit notes or the man using them is asked to contact Northumbria Police on 101 and quote reference 1184 180416.
Anyone who does not wish to speak to police but would like to pass information can contact the independent charity Crimestoppers anonymously on 0800 555 111.