Under the provisions of the Statistics and Registration Services Act 2007, the UK Statistics Authority has a statutory function to assess sets of statistics against the Code of Practice for Official Statistics with a view to determining whether it is appropriate for the statistics to be designated, or to retain their designation, as National Statistics. As the census is not a regular statistical output the normal assessment process is not applicable. Therefore, as part of this obligation, the Authority is undertaking a series of 'special' assessments of the 2011 Censuses in the UK to assess compliance with the code of practice by looking at the censuses’ plans and processes over three phases:

Phase I – assessed compliance with the Code of Practice in respect of those aspects of the code for which it was practicable at December 2009. The phase I assessment was published on 8 March 2010 as report number 28. A document detailing the UK response to the phase I assessment is available to download.

Phase II –assessed compliance with the remaining practices of the code, including a provisional assessment of plans for the publication of various census outputs. The phase II assessment was published on 30 June 2011 as report number 115. In this, the Statistics Authority determined that the 2011 Census outputs could be designated as National Statistics, provided the enhancements listed in section 1.5 were implemented.

ONS has implemented these enhancements, and its response to the phase II requirements is available to download. On 20 June 2012, the board of the UK Statistics Authority designated 2011 Census statistics for England and Wales as National Statistics, in accordance with the Statistics and Registration Service Act 2007, signifying compliance with the Code of Practice for Official Statistics.

Designation can be broadly interpreted to mean that the statistics:

  • meet identified user needs

  • are well explained and readily accessible

  • are produced according to sound methods

  • are managed impartially and objectively in the public interest

Once statistics have been designated as National Statistics it is a statutory requirement that the Code of Practice shall continue to be observed.

Phase 111 started after the first census outputs were published and involved an assessment of census outputs in light of users views. The UK Statistics Authority Special Assessment of the 2011 Censuses in the UK Phase 3 was published 26 November 2015.