One out of 25 transactions at a checkout scanner results in overcharges, costing hundreds of millions of dollars, according to a new report.

In a study entitled Scanners or Scammers, the California Public Interest Research Group (CalPIRG) reports that scanner overcharges at grocery and retail stores are on the rise. Using government data from California's 10 most populous counties in the year ended in July, the consumer group says that 4.1 per cent of scanner transactions resulted in overcharges while 1.6 per cent resulted in undercharges, for a net overcharge of 2.5 per cent.

That's up substantially from the previous year, when net overcharges of 0.7 per cent cost Californians $250 million. CalPIRG did not calculate a total cost for 1997.

However, the retail industry criticised the report, saying scanners are far more accurate than having every price entered into a cash register by hand.

--(New York Times Service)