The iTAPP study investigates the effectiveness of a new method – the 15-method – for identifying and treating alcohol problems among patients in Danish general practice. The method makes it easy for clinicians and patients to discuss alcohol problems and offers a flexible and patient-centered approach for addressing and treating alcohol problems. The method was originally developed in Sweden, where it has proven to be as effective as specialised treatment in treating mild and moderate alcohol dependence in Swedish general practice. The name of the method refers to the fact that each consultation takes a maximum of 15 minutes and that the target group for treatment is patients who score >15 points on the AUDIT (Alcohol Use Disorder Identification Test) screening instrument. Before the iTAPP study, the 15-method was pilot-tested in Denmark and adapted for Danish general practice. In addition to testing the effectiveness of the 15-method, the iTAPP study also aims to assess how effective the method is in reducing alcohol consumption among patients exceeding the Danish Health Authority’s limits. Finally, it will be evaluated whether the 15-method can be recommended for nationwide roll-out. The study was designed as a stepped-wedge cluster randomised controlled trial. It included 20 general practices in the Region of Southern Denmark, 3 of which had previously participated in the pilot study. The practices were divided into clusters and trained in the 15-method.