A notice has been issued to paying customers who still use physical currency to purchase their shopping in supermarkets.
Those using the wrong notes in popular retailers such as ASDA, Tesco, Morrisons, M&S or Aldi will see transactions rejected as of September, with new law being brought into play.
After the September deadline, old paper £20 and £50 notes will have been officially replaced, with the Bank of England still allowing Brits to exchange their dated currency for a polymer replacement after the cut-off point - The MEN reports.