Pubs have been warned to make sure they have the correct licence in place to operate various games machines.
The Gambling Commission has urged pubs to be on guard against machine suppliers trying to pass off amusement with prizes (AWP) machines as games of skill (SWP).
Publicans need to have specific licences in place for amusement machines and run the risk of facing a fine if they do not. Duty also has to be paid on AWP machines.
They have been told to be particularly wary of machines with prizes above £50 which are more likely to be classed as SWPs.
The Gambling Commission has teamed-up with trade groups including the British Beer & Pub Association to get the message across to licensees.
The Commission's national compliance manager for gaming machines, Stuart McPhee, said: "Put simply, machines that look like casino or bingo games are gaming machines and therefore can only be made available for use with the appropriate licence or permit.
"If you are making prize machines available in your pub, club or arcade and are uncertain of their legal status please check with your supplier or manufacturer that you are not breaking the law."
He added that the commission was investigating suppliers of "non-compliant gaming machines".
Read the full guidance at Gambling Commission