Scammers are targeting South Yorkshire's disabled motorists and charging up to five times more than the going rate for their blue badges.
Officials from Trading Standards said they have received numerous complaints about a copycat website that charges disabled motorists £49 when they can get the badges for £10 from the council.
A spokesperson said: "People searching for disabled blue parking badges can easily end up on the copycat site, because the company behind the site uses online techniques to rank higher in search than the councils who officially supply them. People are often unaware they are on the wrong site.
"You can apply for a disabled blue parking badge from: https://www.gov.uk/apply-blue-badge. Copycat websites charge consumers premium prices for government services they can get for free or cheaper from GOV.UK. If you ever need to search for a government service, don’t use a search engine, go to GOV.UK."
Blue badges are intended to allow drivers to park closer to their destination, such as near the front doors of a supermarket.