There is burgeoning interest in the idea that conspicuous begging displays, when parents are provisioning dependent young, advertise offspring need honestly to parents. Many empirical studies claim to support the theory of honest signalling of need, where parents control resource allocation. The evidence, however, also fits the predictions of recent models for the evolution of costly begging, where offspring control allocation. These models incorporate variation in offspring condition and show that the three main predictions of honest signalling models are also found with models of sibling scramble competition. Consequently, it is difficult to discriminate between the two different modelling approaches from their predictions, despite their having been the focus of much empirical work. In particular, the evidence indicates that the prediction that begging intensity signals offspring need honestly is strongly context dependent. Begging might be ‘honest’ only when the potential for conflict is low and food is not limiting.