Pub-goers in the South East are being encouraged to report licensees that sell alcohol to underage drinkers, as part of a crackdown by the authorities.
Kent County Council's trading standards department is appealing for people to turn in any pubs, clubs, shops or off-licences they suspect of selling alcohol to young people.
The majority of premises in Kent are responsible and request ID, but some ignore the law, the council said.
Licensees currently face prosecution and a fine of up to £1,000 if they are caught selling to underage drinkers. The penalty will rise to £5,000 when the new Licensing Act comes into force.
The council said: "It's in everybody's interest to report retailers that are breaking the law. It's good for the community as a whole and most businesses want to be seen as responsible. We find it is best to adopt an intelligence-led approach."
David Austin, licensee at the Leather Bottle in Belvedere, Kent, applauded the move.
"We don't really have a problem with underage drinkers. Anyone we suspect of being underage we ask for ID and if they can't prove their age they are asked to leave," he said.
"I think everybody should have ID cards. If people have nothing to hide, then what's the problem?"
But Chris Maclean, licensee at the Plough and Harrow in Bridge, Kent, said: "Underage drinking does need targeting, but I'm not sure how many people will really bother to report it.
"Personally I despise the idea of ID cards - they are available on the internet and are so easy to forge."
Kevin Boyle, licensee at the Horseshoe and Castle in Rochester, Kent, said he was sceptical of public involvement in such initiatives. "When you have civil servants paid to do the job, using the public as a detector is a bit of a cop-out," he said.
"I think it is unfair that law-abiding licensees can be criminalized for a minor slip-up."