It was important for ONS to plan and explain how we would maintain the confidentiality of personal information, and for these plans to be assessed to ensure their integrity.

The census undertakings state that census personal information would be used solely for statistical purposes, and treated in strict confidence.

To make sure the plans were robust enough to ensure these undertakings, two assessments were carried out.

Privacy Impact Assessment

A Privacy Impact Assessment (PIA) helps to identify privacy risks, foresee problems and bring forward solutions. It is a process for evaluating a proposal to:

  • identify its potential effects upon individual privacy and data protection compliance

  • examine how any detrimental effects might be overcome, and

  • ensure that new projects comply with the data protection principles.

The assessment was published in November 2009 and is available to download.

Independent Information Assurance Review

The Independent Information Assurance Review was conducted to provide an independent review of the protection to be applied to personal information gathered as part of the 2011 Census.

The first phase of the review was published in February 2011 and the second in June 2012. Both are available to download.