The report starts from first principles, asking whether there is any need for a benefit to relieve the council tax and identifying problems with the very structure of council tax benefit. It goes on to consider whether council tax benefit succeeds in leaving local tax bills affordable for low-income groups, using data from the FRS. Even after allowing for benefit, it is found that council tax bills pose an especially large burden for elderly people. Further, a widespread failure to take up entitlement to benefit is found to be preventing the benefit's cleverly designed rules from actually helping many of those in most need. The problems identified in the design and performance of council tax benefit motivate the consideration of several reforms, which range from outright abolition to minor simplification.