Canada has recently published a new Clinical Practice Guideline on the diagnosis and management of brain death. It states that consent is not necessary to carry out the interventions required to make the diagnosis. A supporting article not only sets out the arguments for this but also contends that ‘UK laws similarly carve out an exception, excusing clinicians from a prima facie duty to get consent’. This is supplemented by the claim that recent court decisions in the UK similarly confirm that consent is not required, referencing two judgements in Battersbee. We disagree with the authors’ interpretation of the law on consent in the UK and argue that there is nothing in Battersbee to support the conclusion that consent to testing is not necessary. Where there is a disagreement about testing for brain death in the UK, court authorisation is required.