Corrective release to XBRL UK Accounts Taxonomies

XBRL UK has issued a corrective release of the 2009 accounts taxonomies to fix a number of missing links between line item tags and dimensions and other minor issues.  The release is available for download from the XBRL UK taxonomies website page at http://www.xbrl.org/uk/Taxonomies/. 

This release is a response to requests and feedback from a number of software vendors.   

The effect of the release is to confirm the dimensions which must be used with particular line items.  By accident, a small number of tags in the UK GAAP and UK IFRS taxonomies were not explicitly attached to any dimensions.  The release inserts the missing links, making clear which dimensions should be used with the tags concerned. 

XBRL UK and HMRC strongly recommend that software vendors use the updated release of the taxonomies in their implementations.  This should avoid risk of incorrect allocation of dimensions to the tags concerned.  Preparers of accounts using manual methods should use the latest release. 

The release is backwards compatible in the sense that iXBRL submissions created with the new version of the taxonomies will be valid with the old.  Submissions created with the old will also be valid with the new, unless they have allocated inappropriate dimensions to the items concerned.  However, HMRC will continue to accept instance documents that comply with the old taxonomies (and therefore, by definition, the new) until further notice.

Taxonomy filenames, namespaces and schema references have not changed.  The new versions are distinguished by updated version numbers in the comment section at the head of files.  The zip files containing the new versions also include the date 2010-07-30 in their filenames. 

An Excel spreadsheet, 2009-Taxonomies-changes.xls, located in a taxonomy changes folder in the taxonomy zips, describes in detail the changes in the corrective release.  

Just over 300 tags have been newly attached to dimensions, with 303 in the UK GAAP taxonomy, four in the Directors Report taxonomy, three in Charities and one in UK-IFRS.  The vast majority of the UK GAAP tags relate to movements in risk levels of financial instruments. 

Other changes include:  

· The ‘Shares – acquisitions’ Hypercube in UK GAAP was switched from open to closed.

· The dimension tags ‘From 30 to 60 days’ and ‘From 60 to 90 days’ in both UK GAAP and UK IFRS were switched to abstract from non-abstract.

· Various spurious numbers in the documentation fields of a number of tags were removed.

Users should consult the Excel spreadsheet for full details of changes. 

Inline XBRL submissions based on the old versions of the taxonomy will continue to be accepted as technically valid by HMRC, but internal risk systems may flag any irregular allocation of dimensions which makes an item nonsensical, increasing the likelihood of a subsequent enquiry.  The preparation of instance documents that comply with the updated taxonomies will avoid this.