ATCS04220 - Advance Tax Certainty Service: Process: Early engagement and clearance applications: Timing of clearance applications to HMRC
Clearances can be requested once a project is sufficiently defined to provide the necessary facts for a clearance to be given.
Clearance applications should be made to allow sufficient time for HMRC to review the application in full, request any additional information required, and determine their opinion in advance of the relevant filing date. This should be no later than 60 working days before the relevant date of filing of the first return which will include the transaction (earlier applications are advised for multi-opinion or complex matters).
As an advance certainty facility, clearances may not be sought on tax issues relating to returns that have been filed, or which were due to be filed.