In Australia, legal assistance services – such as legal aid commissions and community legal centres – provide free or subsidised legal advice, primarily to people on low incomes. Surveys show that on average about half the population experiences a legal problem each year, so potential demand for these services is high. In the context of restricted funding, there is increased interest in targeting services to those in greatest need. The challenge is in identifying these individuals and where they live so that services can be designed appropriately to meet their needs. This paper describes the development of the Foundation’s Need for Legal Assistance (NLAS) indicator which uses census data to assess potential demand by geographic location. It provides a count of the number of people who are most likely to need public legal assistance services if they were to experience a legal problem.