Taxation (International and Other Provisions) Act 2010 section 76

Conclusiveness of amounts stated in interest restriction return

Section 76 explains when amounts stated in an interest restriction return become final and conclusive for corporation tax purposes, and the circumstances under which they can still be changed.

• Amounts in an interest restriction return that can no longer be altered are treated as conclusively determined for corporation tax purposes, but this rule does not apply to amounts also stated in a company tax return.
• An amount becomes unalterable only when the return has not been superseded, the filing time limit has passed, any enquiry has been completed, and any appeal period or appeal proceedings have concluded.
• The applicable time limit is normally the standard deadline for submitting the return, but a later deadline applies where extended time limits have been imposed following certain HMRC actions.
• Even after an amount becomes conclusive, HMRC retains the power to open enquiries where errors are discovered under extended time limits, and to make its own determinations in certain circumstances.