Comprehensive apologies are effective strategies to solve interpersonal conflict and promote reconciliation. However, transgressors tend to avoid providing comprehensive apologies because it is more threatening to do so. As a result, transgressors usually offer perfunctory apologies and hinder their own chances of being forgiven. Given the importance of promoting high-quality apologies, we investigate the role of moral identity in increasing apology comprehensiveness. Across three studies using a combination of experimental and correlational designs with autobiographical recall paradigm, we demonstrate that transgressors high in moral identity feel guiltier after committing a transgression. As a result, they offer more comprehensive apologies. Moreover, the effects of guilt on transgressors' apologizing are conditional on the perceived apology effectiveness. Guilt is particularly important to boost apology quality when perceived apology effectiveness is low. In such cases, guilt leads transgressors to make more reparative efforts towards reconciliation despite the low possibility of apology's acceptance.