A travel company based in West Sussex has been fined £25,600 for displaying fake holiday offers at four of its branches in Sussex and Kent.
First Choice pleaded guilty at Horsham Magistrates' Court for promoting the offers in Bognor Regis, Burgess Hill, Gillingham and Canterbury.
Trading Standards, which brought the prosecution, said the result sent out a clear message to the travel industry.
First Choice said it would retrain staff to stop it happening again.
"However we are considering appealing about the level of fine imposed," it added in a statement.
Bruce Treloar, from West Sussex Trading Standards, said travel agents' window cards had been a big issue with trading standards for some years.
"But this is really the first time in West Sussex that we have taken legal action to try and stop the malpractice which is putting a window card with an advertised price for a holiday which either isn't available or it's only available at a higher price."
In court First Choice, which has its head office in Crawley, said there were systems in place to check on the window cards but those checks weren't being carried out by staff or their checks weren't being recorded.
The fine of £2,400 for each of the 16 charges under the Trades Descriptions and Consumer Protection acts was reduced to £1,600 following the firm's guilty plea.