Prevalence of intellectual disability (ID) ranges from 0.05 to 1.55%. A total of 10–15% of the people with ID present with challenging behaviour (CB). This causes a significant strain on mental health services. People with ID often end up staying in psychiatric inpatient units for longer periods. Most people with ID move out of their family home to various care settings due to severity of their behavioural difficulties. This descriptive study shows characteristic features of people with ID and CB and financial costs to look after them in the community. This study highlights the importance to improve services to manage challenging behaviour, which may lead to better quality of life to the person with CB and reduction in financial pressures.