The case of Northern Ireland and ex-IRA informers demonstrates the difficulty of dealing with the informer legacy post-conflict. We explain why Sinn Féin and the UK state have dealt with some conflict legacy cases involving informers but not with others. Contemporary political and reputational reasons are an important explanation, but there are also legal considerations and communal pressures at play. Divisions amongst alleged and self-confessed informers further facilitate this unstructured approach to legacy. These difficulties with informers’ legacy are not unique to Northern Ireland. Similar challenges in reconciling former state agents with paramilitaries are evident across other conflicts.