HUDDERSFIELD people have been warned to be on their guard against postcards which look as though they come from the Royal Mail.
Trading standards are investigating complaints about official-looking notes saying a radio is awaiting collection at a dispatch centre.
To arrange delivery, people have to ring up and quote a security number on the card.
Tiny print at the bottom warns that the calls cost £1.50 a minute and last up to four minutes.
Dr Tony Murphy is among Huddersfield people who received the card.
He said: "It's just terrible. There might be many people expecting Christmas gifts who will fall for this."
The company behind the cards is called Glide Delivery, which uses a PO box address at Ealing in west London.
Doug Love, trading standards officer, said: "Our advice to residents, if they receive unexpected mail of this kind, is to be cautious and always check the small print."