The Trading Standards Institute (TSI) has called for a ban on websites selling "novelty" IDs that are used by under-18s to try to buy alcohol in pubs.
A new survey by the TSI found that one in 14 youngsters aged 14 to 17 carry false ID to buy age-restrictive products or enter bars.
Brandon Cook, the TSI's lead officer on underage sales, told the Consumer Affairs & Trading Standards Conference in Manchester: "It should be an offence to supply this type of card and to use them. Based on the survey findings, which show 7% of underage teens carry fake ID and half get theirs off the Internet, we estimate there could be at least 100,000 in circulation and probably more.
It should be an offence to supply this type of card and to use them.Brandon Cook, the TSI's lead officer on underage sales
"Young people buy these cards with the aim of trying to prove they are older than they really are. This completely undermines our work to encourage retailers to check a person's ID before selling age-restricted products to them - for this reason alone they should be banned."
The TSI said fake IDs, including copycat driving licences and acceptable age verification cards, are "readily available on the Internet for as little as £10".
Cook added: "All fake ID should be included under the definition of identity documents as defined in the Identity Cards Act 2006. This would make it an offence to supply and use the cards."
Graham Rowson, licensee of the Plungington Tavern in Preston, Lancashire, said: "I definitely think novelty IDs shouldn't be allowed.
"But if they are being used and a licensee accepts them, you have to say they are being gullible and you should question their suitability to continue as a licensee."
The tip of the iceberg
Pub and club staff in Warrington, Cheshire, seized 85 fake or falsified IDs in one month, the TSI revealed.
Documents seized during May included 10 fake IDs, 36 doctored driving licences and 33 falsified passports.
Diane Shaughnessy, Warrington Trading Standards Underage Sales (Alcohol) co-ordinator, said: "This gives a snapshot of the situation, but we think this is just the tip of the iceberg."
Crackdown is 'heavy handed' says Humphreys
Robert Humphreys, chairman of the PASS proof of age scheme, said a crackdown on producers of novelty cards is "heavy handed and unlikely to be effective."
He said: "My view is that this is something of a distraction. Legislation is already in place covering all underage purchasing, sales and proxy purchases, except for proxy purchases of tobacco from 1 October.
"Attempting to stamp out novelty cards or to drive websites off the internet seems both heavy handed and unlikely to be effective.
"I do not believe that criminalising young people for carrying novelty cards about is appropriate or necessary, whereas any attempt to make a purchase of age-restricted goods or services is already covered by existing legislation.
"PASS has no evidence suggesting that the successful use of novelty cards to gain access or make purchases illegally is occurring, even though there may well be the large number of such cards about that the survey referred to by the TSI suggests."
Humphreys urged people checking ID to look out for the PASS hologram. "Novelty cards do not carry the PASS hologram, and any attempt to forge the PASS hologram would be a criminal offence and would be pursued with vigour."