ONS has conducted its annual review of seasonal adjustment of the monthly claimant count series and the Nomis data set claimant count - seasonally adjusted has been revised back three years to Jan 2001. All other Nomis claimant count data sets are not seasonally adjusted so are not affected by these revisions. Further details are available from the article:

Seasonal adjustment review of the claimant count (Adobe pdf, 180kb)

ONS have introduced a new seasonally adjusted series of claimant count stocks by age and duration. The data, which are only available at UK level, are described in the above article and can be downloaded as an Excel spreadsheet from the link below:

UK claimant count by age and duration - seasonally adjusted (Excel spreadsheet, 137kb)