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iXBRL 2.0 – where are we three years on?

written by Editor, 4 March 2014

Blog by Gary McCombe, Digita Corporation Tax Product Specialist

It seems only yesterday that the mandatory iXBRL filing of Corporation Tax was introduced by HMRC on 1 April 2011.

iXBRL filing of Corporation Tax

Mandatory iXBRL filing of Corporation Tax was introduced by HMRC on 1 April 2011.

Whilst HMRC introduced a ‘soft landing period’ to give practices breathing room, the initial 6 months showed teething problems with the new requirements. However, provided that a ‘best effort’ was made and a set of mandatory tags was used, HMRC would be satisfied but would expect an improved level of tagging in the next period.

Three years on, filing success levels have improved and we are now entering into the next phase of iXBRL. The soft landing period may have ended and although there’s no draconian hike in HMRC’s expectations – agents/companies will be expected to improve tagging over time.

2014: two new taxonomies

This year sees the introduction of two new taxonomies – mandatory for Accounting Periods ending on or after 1 April 2014:

Corporation Tax Computation Taxonomy

Full taxonomy is removed and the minimum tagging set (with some additions) becomes the sole computation taxonomy. Various ‘under the hood’ changes have also been made with the result being that this is effectively a completely new taxonomy.

Detailed Profit & Loss (“DPL”) Taxonomy

The DPL taxonomy has been added to fill gaps in the information HMRC receives, but there are still issues with this, i.e. it is not mandatory to include a DPL in either the computation or the financial statements; but it is considered the most common way of supporting figures in the computation.

A DPL can be included in either the computation or financial statements, but must be tagged if provided. Including the DPL in both will not cause a filing failure but will result in a higher level of scrutiny (and clearly the figures must also agree).

Companies House will not accept financial statements prepared with a tagged DPL as they reject non-mandatory information.

Future iXBRL developments on the horizon

To replace current UK GAAP taxonomies, FRS 101 and FRS102 taxonomies are expected to be implemented from 1 Jan 2015 – responsibility for UK GAAP taxonomies is now in the hands of the FRC. This will impact on DPL as HMRC expect changes to the DPL taxonomy to be in place in April 2015, but those changes are not known at this time. In future, HMRC is only planning routine budget changes to the Corporation Tax taxonomy.

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