HMRC announced in their recent Agent Update 62 that, from 1 November 2017, they will reject all company tax returns with accounts or tax computations that do not meet Inline Extensible Business Reporting Language (iXBRL) tagging requirements.
Since April 2011, it has been mandatory to file the majority of corporation tax returns online together with the accompanying statutory accounts and tax computations in iXBRL format.
HMRC indicate that the majority of the returns they receive are in the correct iXBRL format but a significant number are still not. From 1 November 2017, returns will be rejected where the accounts or tax computations are not in iXBRL unless:
- Directions under SI 2003/282 allow otherwise (for example certain charities and funds), or
- A dispensation has been granted by HMRC.
If a return is rejected, it will need to be refiled in the correct iXBRL format before the normal filing deadline. Companies may wish to consider filing their next return as early as possible – if a return is rejected close to the filing deadline, this could result in late filing penalties if the iXBRL deficiencies cannot be remedied in time.
In the same Agent Update, HMRC request that, in order to process returns quickly, companies should not submit covering letters or duplicate information in PDF that is already in the iXBRL documents. However, where additional information has to be submitted (for example a loss carry-back claim), companies should continue to submit these as a PDF attachment.
Further information on iXBRL tagging requirements can be found on the GOV.UK website here.