The scheme enables police to trace alcohol being consumed by underage drinkers back to the retailer it was purchased from, but retailers and trade associations have dismissed the move, saying it fails to prove who purchased the product.
MSP Claire Baker said the scheme would target shopkeepers and adults who supplied alcohol to under-18s. But Association of Convenience Stores (ACS) chief executive James Lowman disagreed and called for more to be done to prevent adults buying alcohol on behalf of young people.
He said: "The single biggest way in which underage drinkers get hold of alcohol is by getting it from over-18s who are willing to supply them. Just because the can or bottle held a mark, it would not mean that a store had sold alcohol to an underage person."