Forecourt stores have improved the most in cracking down on sales of lottery tickets to minors, according to Camelot.
The number of forecourt retailers caught out during a first visit by test-purchasers was slashed by a third last year compared with 2004, data from Camelot's Operation Child campaign indicates.
In all, 93% of the 10,386 retailers of all types visited refused to sell to test-purchasers on their first visit, a 5% improvement.
Retailers in Greater London are the worst offenders. More than 15% fell foul of test-purchasers first time around. Scotland and Northern Ireland boasted the best performance.