Tie non-response is having no information regarding the nature of some ties in a network. This lack of information can be present anywhere and has the potential to compromise the results of all network analytic tools. To assess this impact, we used real networks and based simulations on them by introducing varying amounts of tie non-response. This was treated with four tie non-response methods. Blockmodeling, using structural equivalence was applied to the known networks and then to every treated network. The results were compared. The amount of tie non-response, the treatments of tie non-response, the block structure of a network and the level of reciprocity all have an effect of the adequacy of the results of blockmodeling. Reconstruction combined with imputation based on modal values was the best overall treatment. However, non-response treatment methods can work for some networks but not others and we recommend tie non-response treatments based on the form of networks.