By when should you submit financial statements in iXBRL format along with CT1 and what is the penalty for delay 
>Revenue’s current administrative practice regarding iXBRL filing deadlines allows for the filing of Financial Statements in iXBRL format either:
Should a company choose to file its iXBRL Financial Statements within 3 months after the due date for filing the Form CT1, it is important to note that the Form CT1/Corporation Tax Return is deemed to be incomplete where the iXBRL Financial Statements have not been filed during this 3-month period. This can affect refunds/repayments and can lead to refusal of applications for tax clearance. Therefore, companies should ensure to file their iXBRL Financial Statements on or before the due date of the Form CT1 if they wish to ensure that they are not affected by these issues.
It is relevant to note that Section 959A defines “specified return date for the chargeable period” as no later than the 21st day of the 9th month or 23rd day of the 9th month, where return is filed electronically (ROS) following the end of the accounting period.
According to information provided by Revenue in its website, this 3-month administrative practice was introduced from 18 July 2016 and applies for accounting periods ending on or after 1 December 2015. It will continue to apply to subsequent accounting periods until such time as Revenue changes the practice. The practice is subject to review on an ongoing basis and may be withdrawn at Revenue’s discretion. Should Revenue decide to change this practice, an eBrief will issue in advance of the change, affording reasonable time to stakeholders to update their practices.
