To gain a better understanding of the operational problems confronting wastewater pumps due to nonwoven wet wipes, experimental data generated in a laboratory setting were compared with data collected in the field. Pump blockages from a wastewater pump operating in the field under normal conditions were collected and analysed. The types of wet wipes occurring in the blockages were identified and were categorised according to their (claimed) flushability. The clogging effect of comparable wet wipes was then investigated in the laboratory using a wastewater pump with a low resilience against clogging. Profound differences in the clogging effect of the nonwoven wet wipes could be observed. It could also be shown that wet wipes labelled as “flushable” have different clogging effects, depending on whether or not they comply with industry flushability guidelines.