Convenience store owners have often been blamed for allowing alcohol to get into the hands of underage drinkers. But new figures seen exclusively by The Grocer show c-stores are now every bit as responsible as the big retailers when it comes to stopping booze getting into the wrong hands.

The latest figures from test purchasing company Serve Legal show c-stores have made big improvements in passing sting operations this year.

In the first 10 months of the year, 71% of c-stores passed test purchases, compared with 65% last year, putting c-stores on a par with supermarkets for the first time.

Supermarkets also recorded a 71% pass rate, up from 69% last year.

Off-licences lagged behind on 65%, but did show the biggest improvement, up from 55% in 2008.

Serve Legal, which uses a 2,000-strong team of 18 and 19-year olds, carried out 18,112 store visits nationwide in the period.

A test purchase is considered a pass if the mystery shopper is required to provide official ID to complete the purchase. The combined pass rate for the off-trade was 70%, compared with 66% for the on-trade during the period.

The Association of Convenience Stores welcomed small shops' improved pass rate.

"This research shows that small shops are just as responsible as other alcohol retailers," said chief executive James Lowman. "It's pleasing that in the past few years the industry has come together to work on practical steps to tackle underage sales, rather than shifting blame on to one part of the industry."

However, there was still plenty of room for further improvement, he warned. "There are still far too many test purchase failures, and these would be dramatically reduced if retailers adopted and implemented best practice policies with every single sale of an age-restricted product," he said. "Anyone who understands retailing knows the whole industry faces a challenge to improve its performance in this area."

The Serve Legal data revealed some major disparities in pass rates in different areas of the UK. Scotland was the best-performing region, with an overall pass rate of 76%, up from 68% last year, followed by Wales at 75%, up from 58%, and London on 73%. The worst-performing areas were the Midlands and Northern Ireland, which both achieved a rate of just 63%.

Serve Legal director Charlie Mowat warned retailers to be even more vigilant over the festive period as they were likely to face extra scrutiny from police and local authorities.

"Young people are becoming cuter and more daring when it comes to trying to buy alcohol," he said. "At the end of the day, it comes down to whether or not they think they will be served. Retailers need to send out a strong message of zero tolerance."