Mills Convenience Stores is the latest retailer to introduce a Challenge 30 system
instead of the more widely accepted Challenge 21.
The company, which operates 50 licensed shops in the Midlands and northern England, is supporting the
POS material and its own internal test purchase programme.
Rival retailers have already experimented with similar schemes. In 2007 Tesco brought in Challenge 30 in South Yorkshire and Lincolnshire and Asda trialled a Challenge 25 system in 10 Scottish stores.
Mills group managing director Nigel Mills said: "We originally introduced Think 21 and we were still being entrapped - twice with fireworks last October. When we investigated why people were still failing to catch everybody who was under -age we found it was
difficult to make a judgement about how old people were.
"We looked at Challenge 25 and again staff were still guessing. When you go to Challenge 30 there is no doubt - you use common sense but you challenge most people."
Staff who fail an internal or external test purchase can face disciplinary action or even dismissal. "Our internal compliance is now over 70% - when we first started it was 36%," Mills said.
He added that although staff had faced abuse when Challenge 21 was launched, "Think 30 has been welcomed by most of our customers" .
SGF wants pubs
in under-21 ban
Police and council officials say an experiment in which off-licences in a Scottish town were banned from
selling alcohol to under-21s appears to have helped reduce anti social behaviour.
The six-week pilot scheme in Armadale, West Lothian, was extended to nearby Blackridge and Westfield and the results of the trial - the first of its kind in Scotland - are currently being evaluated.
But the Scottish Grocers' Federation has expressed concern that pubs were not invited to take part in the voluntary scheme.
Chief executive John Drummond
said: "I hope that with the extension of the scheme West Lothian Council
invites all licensed premises in the
pilot scheme area to participate in the ban."