Using a mix of survey data from the Household Income and Labour Dynamics in Australia survey and the Household Expenditure Survey, we examine the changing nature of telecommunications expenditure in Australia in the period 2006-2015. We show that it behaves like a core necessity such as food. Households with youth or young adults spend more on telecommunications than other households. The elderly and disadvantaged groups spend less. We propose measures to identify low-income households with relatively high or relatively low expenditure on telecommunications. These measures can be used to identify households that potentially have "telecommunications inadequacy" or "unsustainable telecommunications expenditure".