Aim:The aim of this study is to investigate whether non-medical authorisers of blood component transfusion, in a single centre working at an advanced level, have the theoretical knowledge to potentially undertake this task safely.Background: Authorisation of blood components for transfusion has predominantly been a medical role in the United Kingdom. Advanced Clinical Practitioners (ACP) are increasingly undertaking this role in order to maintain timely transfusion care. Design:A cross sectional study design was utilised for this study which was conducted between 05th March 2018 and the 4th of April 2018.Methods: A total of 81 participants (49 medical authorisers and 32 Advanced Clinical Practitioners of which 21 were nurses and 11 were Allied Healthcare Professionals) working in a single centre completed the BEST-TEST, a previously validated knowledge assessment tool (Transfusion, 54, 2014(Transfusion, 54, , 1225. This study's methods were compliant with the STROBE Checklist. Results:The overall mean was 8.74 out of a possible 20 questions. Doctors scored higher within the basic science domain compared to Advanced Clinical Practitioners (p = .01). This study found the method of training received by its participants was statistically significant with those receiving formal training scoring more than those who had received on the job training from their colleagues (p = .02). When all specialities were compared for differences with the mean correct scores a statistically significant difference was found (p = .01). Conclusion:This study demonstrates there is no statistically significant difference in transfusion medicine knowledge between professional subgroups working in a single centre. Furthermore, there is deficits in the knowledge of all subgroups.Relevance to clinical practice: With advanced practice roles expanding, it is essential that we realise their full potential. There is no current research examining knowledge of ACPs, who could potentially authorise blood components for transfusion, but there are some clear benefits for clinical practice such as providing safe, timely and patient centred care.