INTM489270 - The Unassessed Transfer Pricing Profits Process: When is an assessment finalised
UTPP will apply to accounting periods beginning on or after 1 January 2026. This guidance will be updated with detailed examples by 1 January 2026. For earlier accounting periods please use the diverted profits tax guidance at INTM489500
An assessment is finalised when it can no longer be varied, whether by HMRC, the customer or the tribunal on an appeal notified to it. This will happen when the period for amendments has ended and either no appeal is made, or if an appeal is made then the appeal is finally determined.