Our grasp of biodiversity is fine-tuned through revisionary taxonomy. If species exist in nature and can be discovered with available techniques, revisions should converge on broadly shared interpretations of species.Here species are recognised using integrative assessment, focussing on whether there is corroboration between evidence from coalescents in the COI gene and evidence from morphological divergences. Retrospective analysis of progress between 2011‒2019 in global analyses of bumblebees in two contrasting groups examines convergence on stable solutions within each group as samples were accumulated.Results show that convergence was slow to be achieved because of initial under-representation of rare species despite directed sampling to increase evenness.Filtering out short sequences with ambiguous data had limited value for improving convergence. Filtering to retain only unique alleles was more successful in reducing the over-sampling effects that can promote acceptance of false cryptic species.In addition, results for discriminating polytypic and cryptic species when using UAF are better supported by patterns in genetic divergence with geographical distance . Consequently, the UAF approach was better able to clarify the distinction for long-problematic cases of cryptic bumblebee species. In summary, these results show that reliable taxonomic revision may be difficult to achieve quickly.