There is increasing awareness of the risks when acting for a client whose competence to instruct could be disputed. The inevitable challenge lies in the expectation that legal professionals should be able to identify what are often very subtle indicators of psychiatric or cognitive compromise. With specialist psychiatric evaluation, we have found that in many cases solicitors’ intuitive suspicions are often well-founded and psychiatric compromise is identified. In other cases, it may be that despite the presence of a psychiatric condition, competence can be confirmed and the client’s solicitor can continue to act with the reassurance of an expert psychiatric opinion. Early signs of dementia or the subtle effects of mild brain injury can also undermine a client’s ability to evaluate matters of complexity and provide instructions in a sufficiently cogent manner. In such cases, a psychometric evaluation by an expert psychologist will prove invaluable in determining how to proceed.