A significant number of calls made to Kids Help Line are seen by the organisation as not requiring counselling support, but are rather young people testing or "checking out" the service. Although the status of many of these "testing calls" is self-evident, determining the authenticity of others presents the helpline counsellors with a dilemma: confronting the caller if they have doubts about the caller's reason for calling while, at the same time, avoiding a premature challenge when the call is genuine. We examine the various interactional strategies that the counsellors artfully deploy in their determination of the status of a call. Outright challenges are rare, and counsellors typically will employ devices that announce their suspicions indirectly and which, at the same time, seamlessly accomplish the mundane business of responding to a call in ways which treat the callers with respect. (Contains 5 endnotes.)