Pat Mulhall from Revenue’s iXBRL Business Team discusses the implications of the commencement of compulsory filing of iXBRL financial statements for Corporation Tax payers.
This year, the 1st October is a red-letter day in the Corporation Tax calendar. Since November 2012, Corporation Tax filers have optionally been able to file iXBRL  financial statements. However, from 1st October 2013Phase 1 of iXBRL mandation commences and thereafter mandated filers making their Corporation Tax return in respect of accounting periods ending on or after 31st December 2012, must submit financial statements in iXBRL format to Revenue. These iXBRL returns may be filed with, after or before the CT1 Form through ROS (Revenue On-Line Service). Similar to the ROS roll-out strategy, Revenue have adopted a progressive approach to the roll-out of iXBRL Mandation. Phase 1 applies to customers of Revenue’s Large Cases Division (LCD) .
From the start communications and consultation have been central to Revenue’s iXBRL approach. Since the publication of the iXBRL Consultation Document in December 2011, this engagement has continued through mechanisms such as the Revenue iXBRL Software Vendors Forum and the iXBRL Taxes Administration Liaison Committee (TALC) sub-committee. So, iXBRL Mandation will not be a surprise to LCD Corporation Tax customers or their agents. Indeed to prevent iXBRL surprises, during the Summer Revenue emailed mandated customers and their agents confirming the scope and schedule of Phase 1. These emails also restated the need for LCD Corporation Tax filers to familiarise themselves with their iXBRL obligations and to consider and make the necessary arrangements to ensure compliance. Remember, post-mandation iXBRL financial statements will be a requisite component of a company’s Corporation Tax return. So while Revenue will take cognisance of difficulties encountered with initial filings, iXBRL returns should be given attention and importance comparable to that afforded to a CT1 Form.
Non-LCD companies, outside the Phase 1 mandate, may of course still file iXBRL returns on an optional basis. However, Revenue have recently published details of ‘Phase 2 of Mandatory iXBRL Filing’ giving notice of the extension of the iXBRL filing obligation in 2014 and 2015 to all Corporation Tax filers. In the interim, Revenue strongly encourages non-mandated companies to avail of the opportunity to prepare, presented by optional filing, to effectively “cut their teeth” and become iXBRL ready. Experience in other jurisdictions where such filing obligations have been introduced has shown that filers who delayed preparations for the transition to iXBRL were more likely to experience difficulties and incur unnecessary costs.
If you are unsure whether you or one of you clients are LCD customers (and consequently subject to Phase 1 Mandation), check with your Regional/District Tax Office. If you require further information about Revenue’s iXBRL filing requirement and schedule, please visit the Revenue iXBRL webpage or the Revenue iXBRL Frequently Asked Questions webpage or contact Revenue’s iXBRL Business Team at [email protected] .
 iXBRL (inline eXtensible Business Reporting Language) is a language which allows financial information to be communicated and presented in a format that may be recognised and read by both people and computers.
 In the case of Securitisation Special Purposes Vehicles (SPVs), to which Section 110 Taxes Consolidation Act 1997 refers, the mandation date has been extended to 1st May 2014.