CFM99010 - Interest restriction: administration: penalties: penalty for failure to notify that a return contains estimates after 36 months
TIOPA10/SCH7A/PARA27(5)
Under TIOPA10/SCH7A/PARA 27, an interest restriction must identify any estimated information. If a return still contains estimated information 36 months after the end of the period of account to which the return relates, the reporting company must notify HMRC to this effect within 30 days, see CFM98540.