Background and aim Adjustments for under‐reporting in alcohol surveys have been used in epidemiological and policy studies which assume that all drinkers underestimate their consumption equally. This study aims to describe a method of estimating how under‐reporting of alcohol consumption might vary by age, gender and consumption level. Method The Canadian Alcohol and Drug Use Monitoring Survey (CADUMS) 2008 to 2010 (N= 43,371) asks about beverage specific ‘yesterday’ consumption (BSY) and Quantity‐Frequency (QF). Observed drinking frequencies for different age and gender groups were calculated from BSY and used to correct values of F in QF. Beverage‐specific correction factors for quantity (Q) were calculated by comparing consumption estimated from BSY with sales data. Results Drinking frequency was underestimated by males (Z=24.62, p<0.001) and females (Z=17.46, p<0.001) in the QF as assessed by comparing with frequency and quantity of Yesterday drinking. Spirits consumption was underestimated by 65.94% compared with sales data, wine by 38.35% and beer by 49.02%. After adjusting Q and F values accordingly, regression analysis found alcohol consumption to be under‐estimated significantly more by younger drinkers (e.g.82.9 ±1.19% for underage drinkers vs 70.38 ±1.54% for those 65+, p<0.001) and by low risk more than high risk drinkers (76.25 ±0.34% vs 49.22 ±3.01%, p<0.001). Under‐reporting did not differ by gender. Conclusions Alcohol consumption surveys can use the Beverage‐Specific Yesterday method to correct for underreporting of consumption among sub‐groups. Alcohol consumption among Canadians appears to be under‐reported to an equal degree by men and women. Younger drinkers underreport alcohol consumption to a greater degree than do older, while low risk drinkers underestimate more than do medium and high‐risk.