CIPFA acknowledges that data matching and the single person discount is a complicated legal area. It should be recognised that the use of data matching, including the use of electoral roles is merely a starting point that can be used to narrow the sample size for fraud detection purposes. As you have pointed out, the single person discount applies where there is only one person in a household liable for council tax meaning that the existence of more than one person living at an address does not necessarily indicate fraud. It is for this reason that data matching relies on a number of data sources and is only one tool local authorities use to focus their fraud investigations.
This question also arose at a workshop on fraud during the conference. The respondent said that his authority had sought a legal opinion and that although the law is complicated in this area it had concluded that they had powers to use data for the detection of fraud.
In that case CIPFA ought not to have put its name on a document stating that library records if up to date were reliable guides to entitlement to a single person discount.
