This article considers the current state of the law concerning justification of potentially discriminatory treatment in the area of social security under the European Convention on Human Rights. Over time the UK courts have become familiar with the Convention and have improved their interpretation of human rights law and, in particular, non-discrimination under Article 14 of the Convention. The final step in this process is the consideration of proportionality in relation to the justification of potentially discriminatory provisions. There have been a number of recent important decisions on this issue from the Supreme Court including the Recovery of Medical Costs ruling, the ‘Benefit Cap’ decision and Mathieson. The article discusses how the law may develop in this area. This is of particular interest in a social security context in that the Supreme Court has yet to hear the appeal in the ‘bedroom tax/over-accommodation penalty’ ruling