Abstract Study question As there are no agreed standards for bench marking in cycles involving donation and surrogacy, how do we measure performance for these treatment types? Summary answer Until an international consensus is undertaken, we must define benchmarks using both in-house and published data from the Human Fertilisation and Embryology Authority (HFEA) register. What is known already Treatment cycles involving donor gametes or surrogacy have increased exponentially in recent years (Horsey, 2023; HFEA, 2020). Key performance indicators (KPIs) are critical for monitoring treatment effectiveness and safety. The Vienna Consensus (2017) is the accepted standard against which clinics should measure performance. However, the publication does not include data on cycles involving donation and surrogacy. In the absence of agreed standards, it is difficult for clinics to measure efficacy for these patient groups. Defining benchmarks for such cohorts is particularly challenging as the gametes used in donation and surrogacy treatment types may come from both fertile and sub-fertile populations. Study design, size, duration Retrospective analysis of anonymised United Kingdom (UK) data, published by the HFEA, from 2014 to 2018, was performed. Outcomes for 26290 donor intrauterine insemination (DIUI), 12262 in vitro fertilisation (IVF), 11341 intracytoplasmic sperm injection (ICSI) and 12453 frozen embryo transfer (FET) cycles, all using donor gametes, were included in this study. In cycles where surrogacy was indicated, gamete origin could not be determined, preventing the data from being included in this study. Participants/materials, setting, methods Using the complete HFEA data set, the average live birth rate, for each treatment type (excluding surrogacy), was calculated. This average was considered the target benchmark when comparing the average live birth rates at the clinic. Each quarter, a rolling 12 months of in-house retrospective data was used to assess clinic performance. Warning and action limits were set using standard deviations calculated using the 5 averages obtained from each year of HFEA data included. Main results and the role of chance The average live birth rates determined using the HFEA data, to be used as benchmarks for performance, were as follows; DIUI (13.7%), IVF (42%), ICSI (37%) and FET (36%). It is noteworthy that live birth rates reported by the HFEA were per embryo transfer (ET), rather than per embryo, meaning more than one live birth could be reported per ET. Discrepancies in outcome reporting meant that the national clinical pregnancy rate could not be determined for all treatment types, nor could fertilisation rate. Therefore, the clinic used in-house data to set benchmarks, action, and warning limits for these donor KPIs. Our findings whilst mining the national published data were that no cycle outcomes had been published beyond 2018, meaning these data may not be reflective of current national rates. Also, the national averages calculated will have been affected by individual clinic success rates. Knowing each clinic’s average would create a larger range, from which real world standard deviations could be determined, resulting in more meaningful warning and action limits. Such data was unavailable. The result being that, whilst UK national data is publicly available, it is flawed and insufficient for creating robust benchmarks that clinics can measure themselves against. Limitations, reasons for caution No national data, beyond 2018, is available for use in bench marking. Waiting for live birth data will delay any actions prompted by under-performance. Individual clinic success rate will have impacted the national average. Both fertile and sub-fertile populations will be included in both data sets. Wider implications of the findings The available UK data cannot be used to set robust benchmarks for donor or surrogacy KPIs. Small and new clinics are therefore unable to adequately measure their performance. With the increasing uptake of treatments involving donation and surrogacy, it is time for an international consensus on expected outcomes. Trial registration number not applicable