Leading trade associations believe that switching from the current Challenge 21 system to Challenge 25 will make further progress in the battle against under-age sales.
The new policy has been agreed by the Retail of Alcohol Standards Group, which represents the off-trade in discussions with the government. New signage has been produced to support the scheme, which will be made available free of charge to independents.
Challenge 25 had already been adopted by Asda and Morrisons.
Nick Grant, chairman of RASG, said: “Retailers have done much to reduce levels of under-age purchase but we’ve never been complacent and it’s time to go a stage further.
“Feedback from frontline staff suggests they want the freedom to challenge more widely to ensure young people are not breaking the law, either attempting to purchase alcohol for themselves or for others who are under 18. Challenge 25 makes this a reality and raises the bar.”
Home Office Minister Alan Campbell said: “The Challenge 21 scheme has already proven itself to be an effective tool to combat under-age drinking so I hope every retailer will adopt these new guidelines and continue to confront anyone they believe to be under-age or buying alcohol for under-18s.
“We recognise that the majority of retailers take their responsibilities seriously, refusing to sell alcohol to around 1.5 million under-age children every month, and are determined to continue working with them to tackle the problem.
"We will shortly consult on a new mandatory code of practice for alcohol retailers setting out tough new licensing conditions to help tackle alcohol-related crime and disorder.”