Consumers frequently browse online stores via mobile (m-) channels but seldom realize transactions through m-channels. Although this m-purchasing yields an attractive growth opportunity for online retailers, existing research still insufficiently explains m-purchasing (intentions). Hence, this research develops and empirically tests a model of m-purchasing intention. This study's findings suggest that both task-related (e.g., perceived security risk of m-purchasing) and m-channel-related (e.g., perceived security risk of m-channels) factors inhibit consumers' decision to use m-channels for online transactions. Prior experiences with m-purchasing moderate the effect of perceived m-purchasing security risk on m-purchasing intention; the effect is stronger for experienced than for inexperienced consumers.