The firm contacts exhibitors by mail, prominently displaying the Harrogate Spring Flower Show name.
Harrogate Flower Shows said: "We would like to make it clear that Harrogate Flower Shows has no connection whatsoever with Connect Publisher, who we understand may be based in South America, or any other listing company who may contact you.
"We understand that the letter asks you to complete a form confirming your details. By signing the form you would be committing to a listing on International Fairs Directory, at a cost shown in small print, for three years or more. This wording is contained in small print on the form and should be read carefully."
Four Oaks Trade Show has also warned exhibitors to be wary if they are sent similar communications.