INTM489890 - Diverted Profits Tax: notification, charging and payment: time limits and penalties
Where a company has a duty to notify that it is potentially within the scope of DPT, notification must be made within 3 months of the end of the accounting period to which it relates.
There is a tax-geared penalty for failing to do so.
If a company does not notify HMRC within the time limit that it is potentially within the scope of DPT, the period within which a designated HMRC officer can issue a preliminary notice is extended to 4 years after the end of the accounting period.