Since 2008 Australia has held the National Assessment Program: Literacy and Numeracy (known as NAPLAN) for all students in years 3, 5, 7 and 9. Despite the multilingual character of the Australian population, these standardized literacy and numeracy tests are built on an assumption of English as a first language competency. The capacity for monitoring the performance of students who speak languages other than English is achieved through the disaggregation of test data using a category labelled Language Background Other than English (LBOTE). A student is classified as LBOTE if they or their parents speak a language other than English at home. The category definition is so broad that the disaggregated national data suggest that LBOTE students are outperforming English speaking students, on most test domains, though the LBOTE category shows greater variance of results. Drawing on Foucault's theory of governmentality, this article explores the possible implications of LBOTE categorisation for English as a Second Language (ESL) students of refugee background. The article uses a quantitative research project, carried out in Queensland, Australia, to demonstrate the potential inequities resultant from such a poorly constructed data category.