Abstract This article seeks to explore the nature and function of non-renditions in a corpus of transcriptions of 55 authentic interpreted court proceedings from Barcelona (the TIPp corpus). By doing so, it establishes a dialogue with Cheung’s (2017) contribution about non-renditions in court interpreting in Hong Kong. The transcriptions of the TIPp corpus were annotated using the software EXAMARALDA following Wadenjsö’s (1998) distinction between “talk as text” and “talk as activity”. Non-renditions were considered a part of “talk as activity”. A distinction was made between justified non-renditions, i.e. those that were used to ask for a pause to interpret, to ask for clarification, to confirm possibly misheard information and to retrieve parts of the original message in case of a lapsus, and unjustified non-renditions, e.g. when interpreters give advice to the defendants or warn them, when they answer on behalf of defendants, or when they supply information not provided in the original utterances. The findings reveal alarming averages of non-renditions in the bilingual parts of the trial (58.3 per bilingual hour), with a higher ratio of unjustified non-renditions. These findings have a clear correlation with the poor working conditions of court interpreters in Spain and reveal an urgent need for professionalisation of this practice in this country.