Objective: To describe the development of a functional communication assessment. A secondary aim is to illustrate a process for identifying functional communication outcomes in clients with traumatic brain injury (TBI). The TBI Index for Social and Vocational Communication Outcomes (SAVCO) is designed to identify limitations to everyday communication activities that may present following TBI. It was constructed by anchoring communication activities derived from studies within New Zealand into an internationally recognised theoretical construct, the International Classification of Functioning, Disability and Health (ICF). Four key principles: authenticity of the items, attention to context, collaboration and transparency, underpin the assessment. Main outcomes: The article describes the process of developing a TBI measure that is authentic to an intended population. It provides a preliminary description of the SAVCO, its different constructs and the rationale for their inclusion. The SAVCO is an assessment that highlights everyday activities that are relevant targets for intervention for the individual. The client's performance on the identified activities is explored according to the efficiency and manner of executing the activity. The scope and level of the activity are also determined. Conclusions: The development of the SAVCO illustrates a process for identifying relevant and important functional communication activity items and promotes the use of the ICF framework and rating scales. The preliminary findings suggest that the SAVCO has clinical relevance providing speech–language therapists with a functional communication assessment that leads to the identification and measurement of client-centred therapy outcomes.